Send client telemetry attributes in _meta for Extended Telemetry and SQLCommenter

[AjmeraParth132]

Prerequisites

• Search the current open issues

What are you trying to do that currently feels hard or impossible?

The server needs client identity and user-provided metadata (model, user ID, agent ID) on tools/call to propagate into database query logs via SQLCommenter. Currently _meta only carries traceparent/tracestate

Suggested Solution(s)

1. Add telemetry_attributes to MCPMeta with serialization alias dev.mcp-toolbox/telemetry.
2. Accept at call time: pop telemetry_attributes from kwargs before signature validation:
3. Build payload in transport: always include client.name + client.version from transport state; merge user-provided attrs with client. prefix. Attach to _meta on every tools/call

Alternatives Considered

No response

Additional Details

• Only tools/call affected for v1, and telemetry attributes are directly passed to the server.
• An extension to the project will be to enable the same telemetry in initialize and tools/list, and export them with current telemetry as well