git: clarify when NOT to call status/diff/log — cuts agent extra-call rate (measured +21.7 pts)

[sujugithub]

What

Rewrites 7 tool description strings in src/git/src/mcp_server_git/server.py. No code or behavior changes — only the text agents read when choosing tools.

Why

I measured how a mid-tier agent actually uses this server (12 realistic scenarios × 5 runs each, live server, every tool call recorded). Tool selection is already excellent — 100% hit rate, the diff-trio naming works. The failure mode is ritual verification calls: after git_add, agents call git_status or git_diff_staged to check it worked; before git_show HEAD, they call git_log to find a hash they don't need. A quarter of all runs were padded this way.

Measured effect of this diff (nothing else changed)

metric	before	after
tool hit rate	100%	100%
argument correctness	100%	100%
strict success (right tool + args + no extra calls)	75.0%	96.7%

Method: agent = gpt-oss-120b (deliberately mid-tier — weaker agents are hurt most by underspecified descriptions), N=5 runs per scenario, descriptions applied via in-memory override so before/after used the identical server build. Happy to share the full per-run data and scenario suite, or re-run against any revision of the wording.

Notes

• The pattern in each rewrite: state that the operation is complete on success ("does not require calling git_status to verify"), and say which sibling tool covers the adjacent intent.
• One deviation from the measured text: the tested git_show wording implied revision was optional; since GitShow.revision is required, this PR says Pass revision=\"HEAD\" instead — same intent, schema-accurate.
• The measurement harness (scenarios + runner) is being open-sourced; I'll link it here once public.

🤖 Generated with Claude Code