DO-1: add an integration test (test/mock/tool-timing-server.test.mjs) that
constructs a real createDocmostMcpServer with a spy onMetric, links a Client
over InMemoryTransport, invokes get_workspace (no input schema, so the wrapped
handler always runs) and asserts onMetric fired with
("mcp_tool_duration_seconds", <number>, { tool: "get_workspace" }). This locks
that the monkeypatch wraps every tool AND labels with the registration name —
which the isolated timeToolHandler unit test does not. Mutation-verified
(mislabel -> test fails). The tool's expected backend failure (ECONNREFUSED)
is tolerated: the wrapper times in a finally on throw too, so the metric fires.
DO-2: reword the mcp.service.ts "zero overhead when disabled" comment to
"negligible overhead" — the registerTool wrapper still runs performance.now()
+ an async try/finally per tool call when onMetric is undefined (the
`onMetric?.()` short-circuits the label build; cost is immaterial at
tool-call rate), so "zero" was literally inaccurate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
agent_coder
8f5f5877b3