What are agent skills?
An agent skill is a folder with a SKILL.md file. The file tells an AI agent how to do one specific job.
What is inside a skill
The SKILL.md file starts with a short header. The header has a name and a description. Below that are the instructions. A skill can also hold scripts, templates, or reference files.
--- name: pdf-tools description: Read, fill, and merge PDF files. --- # PDF tools Steps the agent should follow...
How skills load
The agent reads only the name and description at first. That keeps it fast. When your task matches the description, the agent loads the full skill.
Which agents use skills
Claude, Claude Code, Codex, Cursor, Gemini CLI, and OpenClaw can all read SKILL.md skills. The folder path differs by tool. See the install guide.
Claude skills vs agent skills
Same idea, different name. Anthropic started with "Claude skills". Other tools adopted the same SKILL.md format, so people now say "agent skills".
Find skills
Start with Claude skills, Claude Code skills, Codex skills, or Cursor skills.
Questions
What is SKILL.md?
The main file of a skill. It has a name, a description, and instructions for the agent.
Are skills the same as MCP servers?
No. A skill is instructions the agent reads. An MCP server is a program that gives the agent new tools. See Skills vs MCP.
Do I need to code to use a skill?
No. You copy a folder into the right place. Some skills include scripts that the agent runs for you.