Skills from my own Claude Code setup. Each folder is a skill: Claude reads the description in SKILL.md and loads the rest when a task matches it.
- defect-closure - once a bug is found, close the whole class of bugs, not only the one case. A ladder of fixes from "make the bad state unrepresentable" down to "a rule in CLAUDE.md", and a check that the fix really fires.
- measurement - rules for measuring latency, tokens and cost. Most of them come from a case where a number lied: a fast response that was a 404, a model that looked faster because it was timed without the real prompt.
- layout-audit - a script that opens a page at desktop and phone widths and reports what a person would call broken: overflow past the screen edge, clipped or overlapping text, text too small to read. It measures the DOM instead of guessing from a screenshot.
- webapp-testing - how to check a web app in a real browser. The mechanics live in the playwright-cli skill, which Playwright ships itself; this one is the policy around it.
To use one, copy its folder into ~/.claude/skills/. layout-audit needs Node.js and @playwright/cli installed globally.