[Codex Thread
019edc37-5345-7272-92c9-bf5494cf3819](https://codex-thread-link.openai.chatgpt-team.site/thread/019edc37-5345-7272-92c9-bf5494cf3819)
## Summary
- count MCP `CallToolResult.isError` responses as failed calls instead
of successful transport-level calls
- add `codex.mcp.call.error` with bounded `error_type` and trusted
plugin-service `error_code` dimensions
- record the same error classification on MCP tool-call spans while
keeping untrusted server error text out of metric labels
## Scope
- no changes to MCP routing, retries, tool behavior, configuration, or
public APIs
- request failures remain grouped as `mcp_request`; separating
connection, timeout, protocol, and JSON-RPC failures requires preserving
typed errors through the existing flattened error boundary
## Testing
- `just test -p codex-core 'mcp_tool_call::tests::'` (75 passed)
- `just fix -p codex-core`
- `just fmt`
- `just test -p codex-core` (2,676 passed; 80 unrelated environment
failures from missing test binaries, sandbox signals, and read-only
paths)
stevenlee-oai
cbcf1f8ca3