What is an Agent Skill?

An Agent Skill is a folder with a SKILL.md file: frontmatter (a name and a description of when to use it) plus Markdown instructions the agent loads on demand. It's the open standard behind Claude Code's skills, and it works — unchanged — across Codex, Cursor, Copilot, and Gemini CLI.

my-skill/
├── SKILL.md          # frontmatter + instructions
├── scripts/          # optional helper scripts
└── references/       # optional supporting docs

Why they matter

A skill turns a workflow you'd otherwise re-explain every session — your review standards, your debugging discipline, your deploy runbook — into something the agent picks up automatically when it's relevant. Write it once; every session benefits.

The catch nobody mentions

There are hundreds of thousands of free skills now. A lot of them don't actually load: a security scan of ~4,000 public skills found 36.8% had a security flaw, and a large share fail basic structural validation. "Free" is not the same as "works."

That's the whole idea behind ours: spec-valid, security-scanned, and eval-tested — with the results published — and re-tested as new models ship so they don't silently rot.

Next

• Install a skill in your agent of choice.
• Learn the prompt-engineering fundamentals a good skill encodes.