MCP metrics attributes error.type and rpc.response.status_code don't have much difference

[spacewander]

Area(s)

area:mcp

What's missing?

In https://opentelemetry.io/docs/specs/semconv/gen-ai/mcp, we have two attributes:

error.type, described as a class of error the operation ended with, and with a note:

error.type: This attribute SHOULD be set to the string representation of the JSON-RPC error code, if one is returned.

rpc.response.status_code, described as an error code from the JSON-RPC response, with a note:

rpc.response.status_code: Usually it represents an error code, but may also represent partial success, warning, or differentiate between various types of successful outcomes. Semantic conventions for individual RPC frameworks SHOULD document what rpc.response.status_code means in the context of that system and which values are considered to represent errors.

IMHO, they are almost the same. Both rpc.response.status_code and error.type would be set to the string representation of the JSON-RPC error code.

So, what are the differences between them?

Describe the solution you'd like

No response

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