MCP

MCP Attributes

Model Context Protocol (MCP) attributes

Attributes:

Key	Stability	Value Type	Description	Example Values
mcp.method.name		string	The name of the request or notification method.	notifications/cancelled; initialize; notifications/initialized
mcp.protocol.version		string	The version of the Model Context Protocol used.	2025-06-18
mcp.resource.uri		string	The value of the resource uri. [1]	postgres://database/customers/schema; file:///home/user/documents/report.pdf
mcp.session.id		string	Identifies MCP session.	191c4850af6c49e08843a3f6c80e5046

[1] mcp.resource.uri: This is a URI of the resource provided in the following requests or notifications: resources/read, resources/subscribe, resources/unsubscribe, or notifications/resources/updated.

mcp.method.name has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
completion/complete	Request to complete a prompt.
elicitation/create	Request from the server to elicit additional information from the user via the client
initialize	Request to initialize the MCP client.
logging/setLevel	Request to set the logging level.
notifications/cancelled	Notification cancelling a previously-issued request.
notifications/initialized	Notification indicating that the MCP client has been initialized.
notifications/message	Notification indicating that a message has been received.
notifications/progress	Notification indicating the progress for a long-running operation.
notifications/prompts/list_changed	Notification indicating that the list of prompts has changed.
notifications/resources/list_changed	Notification indicating that the list of resources has changed.
notifications/resources/updated	Notification indicating that a resource has been updated.
notifications/roots/list_changed	Notification indicating that the list of roots has changed.
notifications/tools/list_changed	Notification indicating that the list of tools has changed.
ping	Request to check that the other party is still alive.
prompts/get	Request to get a prompt.
prompts/list	Request to list prompts available on server.
resources/list	Request to list resources available on server.
resources/read	Request to read a resource.
resources/subscribe	Request to subscribe to a resource.
resources/templates/list	Request to list resource templates available on server.
resources/unsubscribe	Request to unsubscribe from resource updates.
roots/list	Request to list roots available on server.
sampling/createMessage	Request to create a sampling message.
tools/call	Request to call a tool.
tools/list	Request to list tools available on server.