Mcp Attributes

56 attributes in this category.35 stable·21 deprecated

Scrubbing Visibility OTel

56 attributes

Stable Attributes

`mcp.auth.client.name`

stringScrub: ManualVisibility: PublicOTel: False

Registered OAuth client application name associated with the authenticated MCP request. Taken from OAuth client registration metadata (client_name) made available by the authentication layer. This is distinct from the MCP implementation name in mcp.client.name; omit it when the OAuth client name is unavailable.

ExamplesExample DesktopExample CLI

Changelog

next#671Added mcp.auth.client.name attribute

Raw JSON

{
  "key": "mcp.auth.client.name",
  "brief": "Registered OAuth client application name associated with the authenticated MCP request. Taken from OAuth client registration metadata (client_name) made available by the authentication layer. This is distinct from the MCP implementation name in mcp.client.name; omit it when the OAuth client name is unavailable.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "Example Desktop",
    "Example CLI"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Added mcp.auth.client.name attribute"
    }
  ]
}

`mcp.cancelled.reason`

stringScrub: ManualVisibility: PublicOTel: False

Reason for the cancellation of an MCP operation.

Scrubbing ReasonCancellation reasons may contain user-specific or sensitive information

ExampleUser cancelled the request

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.cancelled.reason",
  "brief": "Reason for the cancellation of an MCP operation.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "Cancellation reasons may contain user-specific or sensitive information"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "User cancelled the request",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.cancelled.request_id`

stringScrub: ManualVisibility: PublicOTel: False

Request ID of the cancelled MCP operation.

Example123

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.cancelled.request_id",
  "brief": "Request ID of the cancelled MCP operation.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "123",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.client.name`

stringScrub: ManualVisibility: PublicOTel: False

Name of the MCP client implementation, as declared in clientInfo. This is distinct from the registered OAuth application name in mcp.auth.client.name.

Examplesexample-mcp-client

Changelog

next#671Clarified that the attribute describes declared MCP implementation metadata

v0.3.0#171

Raw JSON

{
  "key": "mcp.client.name",
  "brief": "Name of the MCP client implementation, as declared in clientInfo. This is distinct from the registered OAuth application name in mcp.auth.client.name.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "example-mcp-client"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the attribute describes declared MCP implementation metadata"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.client.title`

stringScrub: ManualVisibility: PublicOTel: False

Display title of the MCP client implementation, as declared in clientInfo.

Scrubbing ReasonClient titles may reveal user-specific application configurations or custom setups

ExamplesExample MCP Client

Changelog

next#671Clarified that the attribute describes declared MCP implementation metadata

v0.3.0#171

Raw JSON

{
  "key": "mcp.client.title",
  "brief": "Display title of the MCP client implementation, as declared in clientInfo.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "Client titles may reveal user-specific application configurations or custom setups"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "Example MCP Client"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the attribute describes declared MCP implementation metadata"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.client.version`

stringScrub: ManualVisibility: PublicOTel: False

Version of the MCP client implementation, as declared in clientInfo.

Examples1.0.0

Changelog

next#671Clarified that the attribute describes declared MCP implementation metadata

v0.3.0#171

Raw JSON

{
  "key": "mcp.client.version",
  "brief": "Version of the MCP client implementation, as declared in clientInfo.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "1.0.0"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the attribute describes declared MCP implementation metadata"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.lifecycle.phase`

stringScrub: ManualVisibility: PublicOTel: False

Lifecycle phase indicator for MCP operations.

Exampleinitialization_complete

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.lifecycle.phase",
  "brief": "Lifecycle phase indicator for MCP operations.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "initialization_complete",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.logging.data_type`

stringScrub: ManualVisibility: PublicOTel: False

Data type of the logged message content.

Examplestring

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.logging.data_type",
  "brief": "Data type of the logged message content.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "string",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.logging.level`

stringScrub: ManualVisibility: PublicOTel: False

Log level for MCP logging operations.

Exampleinfo

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.logging.level",
  "brief": "Log level for MCP logging operations.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "info",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.logging.logger`

stringScrub: ManualVisibility: PublicOTel: False

Logger name for MCP logging operations.

Scrubbing ReasonLogger names may be user-defined and could contain sensitive information

Examplemcp_server

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.logging.logger",
  "brief": "Logger name for MCP logging operations.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "Logger names may be user-defined and could contain sensitive information"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "mcp_server",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.logging.message`

stringScrub: AutoVisibility: PublicOTel: False

Log message content from MCP logging operations.

Scrubbing ReasonLog messages can contain user data

ExampleTool execution completed successfully

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.logging.message",
  "brief": "Log message content from MCP logging operations.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Log messages can contain user data"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "Tool execution completed successfully",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.method.name`

stringScrub: ManualVisibility: PublicOTel: True

The name of the MCP request or notification method being called.

Exampletools/call

Changelog

v0.12.0#420Set is_in_otel=true, attribute exists in OTel MCP registry

v0.3.0#171

Raw JSON

{
  "key": "mcp.method.name",
  "brief": "The name of the MCP request or notification method being called.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": true,
  "visibility": "public",
  "example": "tools/call",
  "changelog": [
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Set is_in_otel=true, attribute exists in OTel MCP registry"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.progress.current`

doubleScrub: ManualVisibility: PublicOTel: False

Current progress value of an MCP operation.

Examples0.250

Changelog

next#671Changed the type to double to support fractional MCP progress values

v0.4.0#228

v0.3.0#171

Raw JSON

{
  "key": "mcp.progress.current",
  "brief": "Current progress value of an MCP operation.",
  "type": "double",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    0.2,
    50
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Changed the type to double to support fractional MCP progress values"
    },
    {
      "version": "0.4.0",
      "prs": [
        228
      ]
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.progress.message`

stringScrub: ManualVisibility: PublicOTel: False

Progress message describing the current state of an MCP operation.

Scrubbing ReasonProgress messages may contain user-specific or sensitive information

ExampleProcessing 50 of 100 items

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.progress.message",
  "brief": "Progress message describing the current state of an MCP operation.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "Progress messages may contain user-specific or sensitive information"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "Processing 50 of 100 items",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.progress.percentage`

doubleScrub: ManualVisibility: PublicOTel: False

Calculated progress percentage of an MCP operation. Computed from current/total * 100.

Example50

Changelog

v0.4.0#228

v0.3.0#171

Raw JSON

{
  "key": "mcp.progress.percentage",
  "brief": "Calculated progress percentage of an MCP operation. Computed from current/total * 100.",
  "type": "double",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": 50,
  "changelog": [
    {
      "version": "0.4.0",
      "prs": [
        228
      ]
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.progress.token`

stringScrub: ManualVisibility: PublicOTel: False

Token for tracking progress of an MCP operation.

Exampleprogress-token-123

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.progress.token",
  "brief": "Token for tracking progress of an MCP operation.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "progress-token-123",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.progress.total`

doubleScrub: ManualVisibility: PublicOTel: False

Total progress target value of an MCP operation.

Examples1100

Changelog

next#671Changed the type to double to support fractional MCP progress values

v0.4.0#228

v0.3.0#171

Raw JSON

{
  "key": "mcp.progress.total",
  "brief": "Total progress target value of an MCP operation.",
  "type": "double",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    1,
    100
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Changed the type to double to support fractional MCP progress values"
    },
    {
      "version": "0.4.0",
      "prs": [
        228
      ]
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.prompt.result.<key>.content`

stringScrub: AutoVisibility: PublicOTel: False

Legacy text content of an indexed message in a multi-message MCP prompt result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

ExamplesSummarize the document.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple messages. <key> is the zero-based position in the original messages array; absent fields do not renumber later messages.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute.

Raw JSON

{
  "key": "mcp.prompt.result.<key>.content",
  "brief": "Legacy text content of an indexed message in a multi-message MCP prompt result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "Summarize the document."
  ],
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple messages. <key> is the zero-based position in the original messages array; absent fields do not renumber later messages.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute."
    }
  ]
}

`mcp.prompt.result.<key>.role`

stringScrub: AutoVisibility: PublicOTel: False

Legacy role of an indexed message in a multi-message MCP prompt result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesuserassistant

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple messages. <key> is the zero-based position in the original messages array; absent fields do not renumber later messages.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute.

Raw JSON

{
  "key": "mcp.prompt.result.<key>.role",
  "brief": "Legacy role of an indexed message in a multi-message MCP prompt result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "user",
    "assistant"
  ],
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple messages. <key> is the zero-based position in the original messages array; absent fields do not renumber later messages.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute."
    }
  ]
}

`mcp.prompt.result.description`

stringScrub: AutoVisibility: PublicOTel: False

Description of the prompt result.

ExampleA summary of the requested information

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.prompt.result.description",
  "brief": "Description of the prompt result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "A summary of the requested information",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.prompt.result.message_content`

stringScrub: AutoVisibility: PublicOTel: False

Content of the message in the prompt result. Used for single message results only.

ExamplePlease provide a summary of the document

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.prompt.result.message_content",
  "brief": "Content of the message in the prompt result. Used for single message results only.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "Please provide a summary of the document",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.prompt.result.message_count`

integerScrub: ManualVisibility: PublicOTel: False

Number of messages in the prompt result.

Example3

Changelog

v0.4.0#228

v0.3.0#171

Raw JSON

{
  "key": "mcp.prompt.result.message_count",
  "brief": "Number of messages in the prompt result.",
  "type": "integer",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": 3,
  "changelog": [
    {
      "version": "0.4.0",
      "prs": [
        228
      ]
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.prompt.result.message_role`

stringScrub: ManualVisibility: PublicOTel: False

Role of the message in the prompt result. Used for single message results only.

Exampleuser

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.prompt.result.message_role",
  "brief": "Role of the message in the prompt result. Used for single message results only.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "user",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.protocol.ready`

integerScrub: ManualVisibility: PublicOTel: False

Readiness indicator for the legacy MCP initialization handshake. A non-zero value indicates that notifications/initialized has completed initialization. Omit for protocol versions without this handshake.

Examples1

Changelog

next#671Clarified that readiness describes the legacy MCP initialization handshake

v0.4.0#228

v0.3.0#171

Raw JSON

{
  "key": "mcp.protocol.ready",
  "brief": "Readiness indicator for the legacy MCP initialization handshake. A non-zero value indicates that notifications/initialized has completed initialization. Omit for protocol versions without this handshake.",
  "type": "integer",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    1
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that readiness describes the legacy MCP initialization handshake"
    },
    {
      "version": "0.4.0",
      "prs": [
        228
      ]
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.protocol.version`

stringScrub: ManualVisibility: PublicOTel: True

Version of the Model Context Protocol used for the operation.

Examples2024-11-05

Changelog

next#671Clarified that the protocol version applies to an operation without requiring a session

v0.12.0#420Set is_in_otel=true, attribute exists in OTel MCP registry

v0.3.0#171

Raw JSON

{
  "key": "mcp.protocol.version",
  "brief": "Version of the Model Context Protocol used for the operation.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": true,
  "visibility": "public",
  "examples": [
    "2024-11-05"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the protocol version applies to an operation without requiring a session"
    },
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Set is_in_otel=true, attribute exists in OTel MCP registry"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.request.argument.<key>`

stringScrub: AutoVisibility: PublicOTel: FalseDynamic

MCP request argument with dynamic key suffix. The <key> is replaced with the actual argument name. The value is a JSON-stringified representation of the argument value.

Scrubbing ReasonArguments contain user input

Examplemcp.request.argument.query='weather in Paris'

Dynamic SuffixYes - the key contains dynamic parts

Changelog

v0.3.0#176

Raw JSON

{
  "key": "mcp.request.argument.<key>",
  "brief": "MCP request argument with dynamic key suffix. The <key> is replaced with the actual argument name. The value is a JSON-stringified representation of the argument value.",
  "has_dynamic_suffix": true,
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Arguments contain user input"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "mcp.request.argument.query='weather in Paris'",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        176
      ]
    }
  ]
}

`mcp.request.argument.name`

stringScrub: AutoVisibility: PublicOTel: False

Name argument from prompts/get MCP request.

Scrubbing ReasonPrompt names can contain user input

Examplesummarize

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.request.argument.name",
  "brief": "Name argument from prompts/get MCP request.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Prompt names can contain user input"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "summarize",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.request.argument.uri`

stringScrub: AutoVisibility: PublicOTel: False

URI argument from resources/read MCP request.

Scrubbing ReasonURIs can contain user file paths

Examplefile:///path/to/resource

Changelog

v0.3.0#171

Raw JSON

{
  "key": "mcp.request.argument.uri",
  "brief": "URI argument from resources/read MCP request.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "URIs can contain user file paths"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "file:///path/to/resource",
  "changelog": [
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.resource.protocol`

stringScrub: ManualVisibility: PublicOTel: False

URI scheme of the MCP resource being accessed, extracted from its URI. This is distinct from the network protocol used to communicate with the MCP server.

Examplesfilepostgres

Changelog

next#671Clarified Sentry-specific semantics and removed the incorrect network attribute alias and deprecation

v0.21.0#581Added messaging.protocol as an alias

v0.12.0#420Deprecated in favor of network.protocol.name

v0.3.0#171

Raw JSON

{
  "key": "mcp.resource.protocol",
  "brief": "URI scheme of the MCP resource being accessed, extracted from its URI. This is distinct from the network protocol used to communicate with the MCP server.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "file",
    "postgres"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified Sentry-specific semantics and removed the incorrect network attribute alias and deprecation"
    },
    {
      "version": "0.21.0",
      "prs": [
        581
      ],
      "description": "Added messaging.protocol as an alias"
    },
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of network.protocol.name"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.resource.uri`

stringScrub: AutoVisibility: PublicOTel: True

The resource URI being accessed in an MCP operation.

Scrubbing ReasonURIs can contain sensitive file paths

Examplefile:///path/to/file.txt

Changelog

v0.12.0#420Set is_in_otel=true, attribute exists in OTel MCP registry

v0.3.0#171

Raw JSON

{
  "key": "mcp.resource.uri",
  "brief": "The resource URI being accessed in an MCP operation.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "URIs can contain sensitive file paths"
  },
  "is_in_otel": true,
  "visibility": "public",
  "example": "file:///path/to/file.txt",
  "changelog": [
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Set is_in_otel=true, attribute exists in OTel MCP registry"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.server.name`

stringScrub: ManualVisibility: PublicOTel: False

Name of the MCP server implementation, as declared in serverInfo.

Examplesexample-mcp-server

Changelog

next#671Clarified that the attribute describes declared MCP implementation metadata

v0.3.0#171

Raw JSON

{
  "key": "mcp.server.name",
  "brief": "Name of the MCP server implementation, as declared in serverInfo.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "example-mcp-server"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the attribute describes declared MCP implementation metadata"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.server.title`

stringScrub: ManualVisibility: PublicOTel: False

Display title of the MCP server implementation, as declared in serverInfo.

Scrubbing ReasonServer titles may reveal user-specific application configurations or custom setups

ExamplesExample MCP Server

Changelog

next#671Clarified that the attribute describes declared MCP implementation metadata

v0.3.0#171

Raw JSON

{
  "key": "mcp.server.title",
  "brief": "Display title of the MCP server implementation, as declared in serverInfo.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "Server titles may reveal user-specific application configurations or custom setups"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "Example MCP Server"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the attribute describes declared MCP implementation metadata"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.server.version`

stringScrub: ManualVisibility: PublicOTel: False

Version of the MCP server implementation, as declared in serverInfo.

Examples0.1.0

Changelog

next#671Clarified that the attribute describes declared MCP implementation metadata

v0.3.0#171

Raw JSON

{
  "key": "mcp.server.version",
  "brief": "Version of the MCP server implementation, as declared in serverInfo.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "0.1.0"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the attribute describes declared MCP implementation metadata"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.session.id`

stringScrub: ManualVisibility: PublicOTel: True

Identifier for an MCP protocol session, when the operation belongs to a session.

Examples550e8400-e29b-41d4-a716-446655440000

Additional Context

Applies to protocol versions and transports that provide MCP session management, including legacy Streamable HTTP sessions. Omit for operations without a protocol session; do not synthesize a session identifier from a request, connection, or conversation.

Changelog

next#671Clarified that the identifier requires a real MCP protocol session

v0.12.0#420Set is_in_otel=true, attribute exists in OTel MCP registry

v0.3.0#171

Raw JSON

{
  "key": "mcp.session.id",
  "brief": "Identifier for an MCP protocol session, when the operation belongs to a session.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": true,
  "visibility": "public",
  "examples": [
    "550e8400-e29b-41d4-a716-446655440000"
  ],
  "additional_context": [
    "Applies to protocol versions and transports that provide MCP session management, including legacy Streamable HTTP sessions. Omit for operations without a protocol session; do not synthesize a session identifier from a request, connection, or conversation."
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified that the identifier requires a real MCP protocol session"
    },
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Set is_in_otel=true, attribute exists in OTel MCP registry"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.transport`

stringScrub: ManualVisibility: PublicOTel: False

MCP transport implementation name, such as the transport class name. This identifies the implementation, not the network transport or application protocol.

ExamplesStdioServerTransportCustomHTTPTransport

Changelog

next#671Clarified Sentry-specific semantics and removed the incorrect network attribute alias and deprecation

v0.12.0#420Deprecated in favor of network.transport

v0.3.0#171

Raw JSON

{
  "key": "mcp.transport",
  "brief": "MCP transport implementation name, such as the transport class name. This identifies the implementation, not the network transport or application protocol.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "StdioServerTransport",
    "CustomHTTPTransport"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Clarified Sentry-specific semantics and removed the incorrect network attribute alias and deprecation"
    },
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of network.transport"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

Deprecated Attributes

These attributes are deprecated and should not be used in new code. See each attribute for migration guidance.

`mcp.prompt.name`Deprecated

stringScrub: ManualVisibility: PublicOTel: False

Name of the MCP prompt template being used.

Scrubbing ReasonPrompt names may reveal user behavior patterns or sensitive operations

Examplesummarize

Aliasesgen_ai.prompt.name

Use gen_ai.prompt.name instead.

OTel uses gen_ai.prompt.name for MCP prompt names

Status: backfill

Changelog

v0.12.0#420Deprecated in favor of gen_ai.prompt.name

v0.3.0#171

Raw JSON

{
  "key": "mcp.prompt.name",
  "brief": "Name of the MCP prompt template being used.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "Prompt names may reveal user behavior patterns or sensitive operations"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "summarize",
  "deprecation": {
    "replacement": "gen_ai.prompt.name",
    "reason": "OTel uses gen_ai.prompt.name for MCP prompt names",
    "_status": "backfill"
  },
  "alias": [
    "gen_ai.prompt.name"
  ],
  "changelog": [
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of gen_ai.prompt.name"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.request.id`Deprecated

stringScrub: ManualVisibility: PublicOTel: False

JSON-RPC request identifier for the MCP request, used to correlate the request with its response.

Examples1

Aliasesjsonrpc.request.id

Use jsonrpc.request.id instead.

OTel models MCP as JSON-RPC, uses jsonrpc.request.id

Status: backfill

Changelog

next#671Removed the session-scoped uniqueness requirement from the request identifier

v0.12.0#420Deprecated in favor of jsonrpc.request.id

v0.3.0#171

Raw JSON

{
  "key": "mcp.request.id",
  "brief": "JSON-RPC request identifier for the MCP request, used to correlate the request with its response.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "1"
  ],
  "deprecation": {
    "replacement": "jsonrpc.request.id",
    "reason": "OTel models MCP as JSON-RPC, uses jsonrpc.request.id",
    "_status": "backfill"
  },
  "alias": [
    "jsonrpc.request.id"
  ],
  "changelog": [
    {
      "version": "next",
      "prs": [
        671
      ],
      "description": "Removed the session-scoped uniqueness requirement from the request identifier"
    },
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of jsonrpc.request.id"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.tool.name`Deprecated

stringScrub: ManualVisibility: PublicOTel: False

Name of the MCP tool being called.

Examplecalculator

Aliasesgen_ai.tool.nameai.function_call

Use gen_ai.tool.name instead.

OTel uses gen_ai.tool.name for MCP tool names

Status: backfill

Changelog

v0.12.0#420Deprecated in favor of gen_ai.tool.name

v0.3.0#171

Raw JSON

{
  "key": "mcp.tool.name",
  "brief": "Name of the MCP tool being called.",
  "type": "string",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "calculator",
  "deprecation": {
    "replacement": "gen_ai.tool.name",
    "reason": "OTel uses gen_ai.tool.name for MCP tool names",
    "_status": "backfill"
  },
  "alias": [
    "gen_ai.tool.name",
    "ai.function_call"
  ],
  "changelog": [
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of gen_ai.tool.name"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.tool.result.<key>.content`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy text content of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

ExamplesThe operation completed.

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.
This is one item's text, not the complete tool result. It must not be aliased or directly backfilled to gen_ai.tool.call.result; reconstructing the complete result requires aggregation.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.content",
  "brief": "Legacy text content of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "The operation completed."
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled.",
    "This is one item's text, not the complete tool result. It must not be aliased or directly backfilled to gen_ai.tool.call.result; reconstructing the complete result requires aggregation."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.content_type`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy content type of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplestextimage

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded even when output capture is disabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.content_type",
  "brief": "Legacy content type of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "text",
    "image"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded even when output capture is disabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.data_size`Deprecated

integerScrub: ManualVisibility: PublicOTel: False

Legacy length of the data string in UTF-16 code units of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonThe length contains no result content.

Examples41024

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.
The JavaScript SDK records data.length. For base64-encoded image or audio data, this counts encoded characters, not decoded bytes.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.data_size",
  "brief": "Legacy length of the data string in UTF-16 code units of an indexed content item in a multi-item MCP tool result.",
  "type": "integer",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "The length contains no result content."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    4,
    1024
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled.",
    "The JavaScript SDK records data.length. For base64-encoded image or audio data, this counts encoded characters, not decoded bytes."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.mime_type`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy MIME type of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesimage/pngaudio/wav

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.mime_type",
  "brief": "Legacy MIME type of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "image/png",
    "audio/wav"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.name`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy resource link name of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesreport.txt

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.name",
  "brief": "Legacy resource link name of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "report.txt"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.resource_mime_type`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy embedded resource MIME type of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplestext/plain

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.resource_mime_type",
  "brief": "Legacy embedded resource MIME type of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "text/plain"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.resource_uri`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy embedded resource URI of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesfile:///project/report.txt

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.resource_uri",
  "brief": "Legacy embedded resource URI of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "file:///project/report.txt"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.<key>.uri`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy resource link URI of an indexed content item in a multi-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesfile:///project/report.txt

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.<key>.uri",
  "brief": "Legacy resource link URI of an indexed content item in a multi-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "file:///project/report.txt"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted for results with multiple content items. <key> is the zero-based position in the original content array; absent fields do not renumber later items.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.content`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

The content of the tool result.

Scrubbing ReasonTool results can contain user data

Example{"output": "rainy", "toolCallId": "1"}

Aliasesgen_ai.tool.call.resultgen_ai.tool.messagegen_ai.tool.outputai.toolCall.resultanthropic.tool_result.content

Use gen_ai.tool.call.result instead.

OTel uses gen_ai.tool.call.result for MCP tool results

Status: backfill

Changelog

v0.12.0#420Deprecated in favor of gen_ai.tool.call.result

v0.3.0#171

v0.2.0#164

Raw JSON

{
  "key": "mcp.tool.result.content",
  "brief": "The content of the tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Tool results can contain user data"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": "{\"output\": \"rainy\", \"toolCallId\": \"1\"}",
  "deprecation": {
    "replacement": "gen_ai.tool.call.result",
    "reason": "OTel uses gen_ai.tool.call.result for MCP tool results",
    "_status": "backfill"
  },
  "alias": [
    "gen_ai.tool.call.result",
    "gen_ai.tool.message",
    "gen_ai.tool.output",
    "ai.toolCall.result",
    "anthropic.tool_result.content"
  ],
  "changelog": [
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of gen_ai.tool.call.result"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    },
    {
      "version": "0.2.0",
      "prs": [
        164
      ]
    }
  ]
}

`mcp.tool.result.content_count`Deprecated

integerScrub: ManualVisibility: PublicOTel: False

Number of content items in the tool result.

Example1

No replacement available at this time.

A count can be calculcated from the value of the gen_ai.tool.call.result attribute.

Changelog

next#669Deprecate the attribute since it is redundant given gen_ai.tool.call.result.

v0.4.0#228

v0.3.0#171

Raw JSON

{
  "key": "mcp.tool.result.content_count",
  "brief": "Number of content items in the tool result.",
  "type": "integer",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": 1,
  "deprecation": {
    "reason": "A count can be calculcated from the value of the gen_ai.tool.call.result attribute.",
    "_status": null
  },
  "changelog": [
    {
      "version": "next",
      "prs": [
        669
      ],
      "description": "Deprecate the attribute since it is redundant given gen_ai.tool.call.result."
    },
    {
      "version": "0.4.0",
      "prs": [
        228
      ]
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.tool.result.content_type`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy content type of the content item in a single-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplestextimage

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded even when output capture is disabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.content_type",
  "brief": "Legacy content type of the content item in a single-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "text",
    "image"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded even when output capture is disabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.data_size`Deprecated

integerScrub: ManualVisibility: PublicOTel: False

Legacy length of the data string in UTF-16 code units of the content item in a single-item MCP tool result.

Scrubbing ReasonThe length contains no result content.

Examples41024

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded only when output capture is enabled.
The JavaScript SDK records data.length. For base64-encoded image or audio data, this counts encoded characters, not decoded bytes.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.data_size",
  "brief": "Legacy length of the data string in UTF-16 code units of the content item in a single-item MCP tool result.",
  "type": "integer",
  "apply_scrubbing": {
    "key": "manual",
    "reason": "The length contains no result content."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    4,
    1024
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded only when output capture is enabled.",
    "The JavaScript SDK records data.length. For base64-encoded image or audio data, this counts encoded characters, not decoded bytes."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.is_error`Deprecated

booleanScrub: ManualVisibility: PublicOTel: False

Whether a tool execution resulted in an error.

Examplefalse

Use error.type instead.

OTel uses error.type set to 'tool_error' when isError is true. Cannot be automatically backfilled due to type mismatch (boolean vs string).

Changelog

v0.12.0#420Deprecated in favor of error.type

v0.3.0#171

Raw JSON

{
  "key": "mcp.tool.result.is_error",
  "brief": "Whether a tool execution resulted in an error.",
  "type": "boolean",
  "apply_scrubbing": {
    "key": "manual"
  },
  "is_in_otel": false,
  "visibility": "public",
  "example": false,
  "deprecation": {
    "replacement": "error.type",
    "reason": "OTel uses error.type set to 'tool_error' when isError is true. Cannot be automatically backfilled due to type mismatch (boolean vs string).",
    "_status": null
  },
  "changelog": [
    {
      "version": "0.12.0",
      "prs": [
        420
      ],
      "description": "Deprecated in favor of error.type"
    },
    {
      "version": "0.3.0",
      "prs": [
        171
      ]
    }
  ]
}

`mcp.tool.result.mime_type`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy MIME type of the content item in a single-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesimage/pngaudio/wav

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.mime_type",
  "brief": "Legacy MIME type of the content item in a single-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "image/png",
    "audio/wav"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.name`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy resource link name of the content item in a single-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesreport.txt

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.name",
  "brief": "Legacy resource link name of the content item in a single-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "report.txt"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.resource_mime_type`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy embedded resource MIME type of the content item in a single-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplestext/plain

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.resource_mime_type",
  "brief": "Legacy embedded resource MIME type of the content item in a single-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "text/plain"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.resource_uri`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy embedded resource URI of the content item in a single-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesfile:///project/report.txt

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.resource_uri",
  "brief": "Legacy embedded resource URI of the content item in a single-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "file:///project/report.txt"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

`mcp.tool.result.uri`Deprecated

stringScrub: AutoVisibility: PublicOTel: False

Legacy resource link URI of the content item in a single-item MCP tool result.

Scrubbing ReasonPreserve automatic scrubbing of server-provided result fields.

Examplesfile:///project/report.txt

No replacement available at this time.

Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.

Additional Context

Registers an existing Sentry JavaScript SDK attribute for compatibility.
Emitted only when the result contains exactly one content item.
Recorded only when output capture is enabled.

Changelog

nextRegister an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill.

Raw JSON

{
  "key": "mcp.tool.result.uri",
  "brief": "Legacy resource link URI of the content item in a single-item MCP tool result.",
  "type": "string",
  "apply_scrubbing": {
    "key": "auto",
    "reason": "Preserve automatic scrubbing of server-provided result fields."
  },
  "is_in_otel": false,
  "visibility": "public",
  "examples": [
    "file:///project/report.txt"
  ],
  "deprecation": {
    "reason": "Capture the complete tool result in gen_ai.tool.call.result instead. This attribute describes only part of the result and cannot be directly backfilled.",
    "_status": null
  },
  "additional_context": [
    "Registers an existing Sentry JavaScript SDK attribute for compatibility.",
    "Emitted only when the result contains exactly one content item.",
    "Recorded only when output capture is enabled."
  ],
  "changelog": [
    {
      "version": "next",
      "description": "Register an existing JavaScript SDK MCP result attribute as deprecated in favor of gen_ai.tool.call.result, without backfill."
    }
  ]
}

Mcp Attributes

Stable Attributes

Deprecated Attributes

mcp.prompt.nameDeprecated

mcp.request.idDeprecated

mcp.tool.nameDeprecated

mcp.tool.result.<key>.contentDeprecated

mcp.tool.result.<key>.content_typeDeprecated

mcp.tool.result.<key>.data_sizeDeprecated

mcp.tool.result.<key>.mime_typeDeprecated

mcp.tool.result.<key>.nameDeprecated

mcp.tool.result.<key>.resource_mime_typeDeprecated

mcp.tool.result.<key>.resource_uriDeprecated

mcp.tool.result.<key>.uriDeprecated

mcp.tool.result.contentDeprecated

mcp.tool.result.content_countDeprecated

mcp.tool.result.content_typeDeprecated

mcp.tool.result.data_sizeDeprecated

mcp.tool.result.is_errorDeprecated

mcp.tool.result.mime_typeDeprecated

mcp.tool.result.nameDeprecated

mcp.tool.result.resource_mime_typeDeprecated

mcp.tool.result.resource_uriDeprecated

mcp.tool.result.uriDeprecated

`mcp.prompt.name`Deprecated

`mcp.request.id`Deprecated

`mcp.tool.name`Deprecated

`mcp.tool.result.<key>.content`Deprecated

`mcp.tool.result.<key>.content_type`Deprecated

`mcp.tool.result.<key>.data_size`Deprecated

`mcp.tool.result.<key>.mime_type`Deprecated

`mcp.tool.result.<key>.name`Deprecated

`mcp.tool.result.<key>.resource_mime_type`Deprecated

`mcp.tool.result.<key>.resource_uri`Deprecated

`mcp.tool.result.<key>.uri`Deprecated

`mcp.tool.result.content`Deprecated

`mcp.tool.result.content_count`Deprecated

`mcp.tool.result.content_type`Deprecated

`mcp.tool.result.data_size`Deprecated

`mcp.tool.result.is_error`Deprecated

`mcp.tool.result.mime_type`Deprecated

`mcp.tool.result.name`Deprecated

`mcp.tool.result.resource_mime_type`Deprecated

`mcp.tool.result.resource_uri`Deprecated

`mcp.tool.result.uri`Deprecated