You have house rules for your coding agent: how commit messages should look, what a code review should check, how meeting notes should be structured. So you paste them into the chat at the start of every session — and by message ten the agent has drifted anyway. Next session, you paste again.
The problem is not memory. The instructions live in your clipboard instead of in a file the agent loads every time. A skill is that file.
A skill is a folder containing one file: SKILL.md. It has two parts.
The YAML frontmatter carries two fields — a name and a description. The description is the trigger: the agent scans the descriptions of its skills to decide which ones apply to your request. So the description does two jobs — say what the skill does, and name the situations where it fires. Write it as "does X. Use when the user asks for Y."
The body is plain markdown: the workflow, the rules, an example. No code, no config beyond the frontmatter.
The smallest skill in my pack generates commit messages, and it shows every part doing a job. Its frontmatter, verbatim:
---
name: git-commit-message
description: "Generates conventional-commit messages from staged changes: type prefix + English imperative subject (≤50 chars) + optional body explaining why. Use when the user asks to write, generate, or polish a git commit message."
---
The workflow is five numbered steps, in execution order:
git status --short, git diff --cached --stat). If nothing is staged, stop and ask — never invent a message out of nothing.feat, fix, docs, refactor, test, chore. A change that mixes types gets split into two commits, not averaged into one.git commit command, not bare text the user has to assemble.
Then come the rules that encode judgment — the things you would otherwise keep correcting in review:
And one worked example, with the expected output:
git commit -m "feat: add CAPTCHA verification to login endpoint" -m "Blocks automated credential stuffing; CAPTCHA valid 5 minutes, account locks 10 minutes after 3 failures."
Finally, the anti-patterns — the failure modes, named explicitly:
Each part earns its place. The description decides triggering. The numbered steps fix the order of operations and include a stop condition. The rules hold the judgment calls. The example anchors the output format better than a paragraph of prose. The anti-patterns tell the agent what to refuse.
Drop the folder into your agent's skills directory, and the agent picks it up by matching the description — no further configuration. If you want working examples first, the five skills in the pack this teardown came from are free and MIT-licensed: commit messages, code review, meeting minutes, technical proofreading, and structured deep research.
Repo: https://github.com/alapha888/agent-skills-en
npx skills add alapha888/agent-skills-en
The structure is the stable part; the rules are yours. Take the workflow you explained three times this week, and write it down once.