creating-agent-skills

Structure a Claude Code Skill with progressive disclosure by using a router-pattern SKILL.md to direct intake, routing workflows, and references. This enforces frontmatter rules, XML body structure, and validation patterns to ensure discoverable, testable skills.

The best way to author a router-pattern Skill is to outline core principles, intake, and routing in SKILL.md, then establish initial references and workflows. This provides a complete blueprint for structure, guidance, and validation.

Claude Skills require strict YAML frontmatter rules and a structured XML body organization. The skill enforces these requirements alongside references organization and workflow design to reduce ambiguity and increase consistency.

Yes, you can audit and upgrade existing Claude Code Skills. The skill provides audit workflows that cover effective skill design, router upgrades, and continual improvement using concrete examples and anti-patterns.

A simple one-file Skill suits basic tasks, while a router-pattern Skill is needed for progressive disclosure with multiple workflows and references. Choosing depends on the complexity of the guidance and validation patterns required.

Claude Skill validation fails when frontmatter rules, XML body structure, or references organization do not match the expected blueprint. Enforcing validation patterns and avoiding anti-patterns ensures your skills remain testable and discoverable.