rulebook-terse-commit - SKILL.md Agent Skill

name: "Rulebook Terse Commit" description: "Terse Conventional Commits generator. Subject ≤50 chars (hard cap 72), body only when 'why' isn't obvious, no filler. Use when user says 'write a commit', 'generate commit', 'commit message', or invokes /rulebook-terse-commit. Independent of the base rulebook-terse mode." version: "1.0.0" category: "core" author: "Rulebook" tags: ["core", "git", "commits", "tokens"] dependencies: [] conflicts: []

Rulebook Terse Commit

Write commit messages terse and exact. Conventional Commits format. Why over what.

Subject line

Format: <type>(<scope>): <imperative summary> — <scope> optional.
Types: feat, fix, refactor, perf, docs, test, chore, build, ci, style, revert.
Imperative mood: "add", "fix", "remove" — not "added", "adds", "adding".
Target ≤50 chars. Hard cap 72.
No trailing period.
Match project capitalization convention after the colon (match the repo's existing history).

Body

Skip the body entirely when the subject is self-explanatory.
Add a body ONLY for: non-obvious why, breaking changes, migration notes, linked issues.
Wrap at 72 chars.
Bullets use -, not *.
Reference issues/PRs at the end: Closes #42, Refs #17.

Never include

"This commit does X", "I", "we", "now", "currently" — the diff says what.
"As requested by ..." — use the Co-authored-by trailer instead.
"Generated with Claude Code" or any AI attribution.
Emoji (unless project convention requires them).
Restating the file name when <scope> already identifies it.

Auto-Clarity

Always include a body for:

Breaking changes (! suffix on type, plus BREAKING CHANGE: footer).
Security fixes (CVE ID when applicable).
Data migrations that touch user data.
Reverts of a prior commit (reference the reverted SHA).
Performance regressions fixed (include before/after numbers when possible).

Terseness is NEVER permitted to obscure these cases — future debuggers need the context.

Examples

New endpoint with non-obvious why

feat(api): add GET /users/:id/profile

Mobile client needs profile data without the full user payload to
reduce LTE bandwidth on cold-launch screens.

Closes #128

Breaking API change

feat(api)!: rename /v1/orders to /v1/checkout

BREAKING CHANGE: clients on /v1/orders must migrate to /v1/checkout
before 2026-06-01. Old route returns 410 after that date.

Simple bug fix — subject only

fix(auth): reject expired tokens on boundary second

Revert

revert: "feat(api): add GET /users/:id/profile"

This reverts commit a1b2c3d. Endpoint caused 5% latency regression
on the hot path; see incident INC-4219.

Boundaries

Only generates the commit message. Does NOT run git commit, does NOT stage files, does NOT amend. Output is a code block ready to paste.

Override: /rulebook-terse-commit off or "stop terse commit" reverts to the model's default commit style.