What Are Agent Skills?
An Agent Skill is a folder that teaches an AI agent one job. It contains a SKILL.md with a name, a description, and instructions — plus any templates, references or scripts the job needs. The agent sees the name and description at the start of a session and loads the full instructions only when a task matches.
That's the whole idea. The clever part is what it replaces: a 2,000-word prompt you paste every time, or a Notion page the model never reads.
What's inside
og-image/
SKILL.md # name, description, steps
references/
layouts.md # long reference material
scripts/
render.ts # optional helper
assets/
font.woff2Only SKILL.md is required. Everything else is loaded on demand — the agent reads the map first, then opens the drawer it needs.
Why they spread so fast
Because the format is boring. A folder of text files works in Claude Code, Codex, Cursor, Gemini CLI, Copilot and Windsurf without a server, an SDK, or a vendor account. The same skill can be committed to a repo and reviewed like code.
Skills vs prompts vs MCP
| Prompt | Skill | MCP | |
|---|---|---|---|
| Lifetime | One message | Reusable | Persistent connection |
| Contains | Instructions | Instructions + assets + scripts | Tools and data |
| Loaded | Always | On demand | On demand |
| Portable | Copy-paste | Copy a folder | Needs a server |
Use a prompt for a one-off. Use a skill for a job you'll repeat. Use MCP when the job needs live data from another system. More detail: Skills vs MCP.
What makes a good skill
- A narrow job. "Make an OG image" beats "help with design".
- A description with trigger words. It's the only thing the agent sees before deciding.
- Explicit output. Size, format, file name, constraints.
- A failure path. What to do when the input is missing.
Where to get them
You can write one in ten minutes, or install one that already encodes a design system. The catalog has 400+ skills across web pages, slides, images and video, each with a preview and an install count.
FAQ
Are skills safe? They're readable text, but they can include scripts. Read before you run — the same rule as any dependency.
Do they work offline? Yes, if the skill and its assets are local and the agent runs locally.
Can I edit a skill? Yes. Fork it and keep your version.