What Is a Claude Skill (SKILL.md)? A Plain-English Guide
What is a Claude skill?
A Claude skill is a folder containing a SKILL.md file that teaches Claude one task. The file starts with a YAML header (name and description) and then gives the steps. Claude only loads the full file when your request matches the description, so you can install many skills without filling its context.
What goes inside SKILL.md?
Three parts: frontmatter (name, description), the procedure (numbered actions, exact commands and values), and optional references to other files in the folder such as templates or scripts.
Why does the description matter so much?
It is the only part Claude reads up front. Write it as when to use the skill: "Use when the user asks to turn a podcast episode into LinkedIn posts." Vague descriptions mean the skill never fires.
Where do skills run?
Claude.ai and Claude Cowork (upload as ZIP in settings) and Claude Code (put the folder in your skills directory). Other agents can read the same Markdown as instructions.
How do I make one fast?
Write it by hand from your own process, or paste a YouTube tutorial into SkillForge and edit the SKILL.md it writes. The step-by-step method is in How to Turn a YouTube Tutorial into a Claude Skill.
FAQ
Is a skill the same as a prompt?
Can a skill run code?
How long should it be?
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