Skill Design - Anthropic Format

A skill is a markdown file (SKILL.md) that teaches Claude how to do a specific job. It transforms Claude from a general-purpose model into a specialist with procedural knowledge, hard rules, and domain-specific judgment. Skills are the most efficient way to embed repeatable expertise into an AI workflow.

The design principle: write the skill as if you're onboarding a sharp new hire who knows nothing about your domain. Be explicit about what good looks like, what's banned, and how to make judgment calls. Show concrete examples. State rules as absolutes, not suggestions.

Skill Anatomy

Every skill is a directory containing a required SKILL.md file and optional supporting files.