log-gotcha

name	log-gotcha
description	Record a newly-discovered gotcha to `.agents/wiki/` BEFORE handoff — the harness's feedback loop. The wiki is how the next agent doesn't repeat your discovery.
triggers	["hit something non-obvious during the task","silent failure / suspicious default / quirk in a library or runtime","before handoff if anything surprised you"]
allowed-tools	Bash Read Write Edit Grep Glob
argument-hint	[--topic <area>]

log-gotcha (principle 8)

Every mistake is a prompt bug. The wiki is how the harness learns: every entry there is one agent-turn the next agent skips because they already know what you discovered. Logging is part of the task, not a separate "good-to-have" step.

When to log

You should log a gotcha if any of these apply to what you just did:

• A test, framework, or runtime did something surprising (e.g. divide(1, 0) returns Infinity not throws; node --test some-dir resolves the dir as a module; console.log after process.exit silently truncates piped output).
• A library default bit you (silent overwrite, surprising coercion, hidden API contract).
• An AGENTS.md rule wasn't loud enough — you almost violated it, or did, until you caught yourself.
• A non-obvious cross-file dependency that someone touching one file would miss.
• A flaky test, an environment-specific assumption, a build-cache surprise.

Do not log taste opinions, style preferences, or things that are already in CONTRIBUTING.md.

How to log

1. Check the wiki first. Run ls .agents/wiki/ and grep -ri "<keyword>" .agents/wiki/ for the most natural keywords. If an existing entry covers it, SHARPEN that entry instead of adding a near-duplicate (the wiki README has a strict admission test on duplication).
2. Pick a topic file. Either an existing one (e.g. troubleshooting.md) or create .agents/wiki/<topic>.md if the area is new (e.g. node-test-runner.md, html-templates.md). Topic names are kebab-case nouns.
3. Write a stub entry using the template below. Keep it terse — 5 lines max.
4. Commit it as part of your fix's diff. Wiki entries are not "after-the-fact paperwork" — they go in the SAME commit/PR as the fix that revealed them, so reviewers can see them.

Entry template

### <short noun-phrase title>
- **Symptom:** what went wrong / how it showed up
- **Cause:** the real root cause (not the symptom)
- **Fix:** the change you made (or wider remediation)
- **Prevention:** one-line rule that would have spared you this discovery
- **Discovered:** <date> in <scenario or task id>

Skill failure modes (explicitly)

• "I didn't really hit a gotcha." Most fixes DO reveal one — you just didn't notice because the fix took less than 5 minutes. The discriminating question is "could the next agent have known this from the existing instructions?" — if no, log it.
• "It's too small." Small gotchas are exactly the ones that vanish from memory by tomorrow.
• "I'll log later." No — log it in the SAME commit. "Later" is how wikis die.

Verification

Before considering this skill complete, confirm with git diff --cached --stat that your wiki entry shows in the staged diff. The memory axis in the harness eval explicitly checks for this: "diff contains a .agents/wiki/ entry" → 1.0; "mentioned in summary but not committed" → 0.5; "silent" → 0.