create-agent-skills

Claude Code skills use a structured format with YAML frontmatter and markdown content to define custom slash commands. You create a SKILL.md file that specifies the command's behavior, dependencies, and dynamic context injection rules.

A Claude skill directory contains a SKILL.md file and supporting resources for complex behaviors, while a command file is a simpler standalone markdown file. You choose a skill directory when you need progressive disclosure or multiple related commands grouped together.

Writing effective descriptions for Claude skills involves clearly defining the task in the YAML frontmatter so the tool is discoverable. You should follow best practices for managing dependencies and structuring your markdown content to ensure optimal performance and seamless integration.

You should use progressive disclosure in Claude skill development when your custom tool requires complex, layered instructions. This technique structures your markdown content to provide dynamic context injection, preventing Claude from being overwhelmed while ensuring detailed behavior when needed.

You audit a Claude skill for quality assurance by running through a provided checklist that validates your YAML frontmatter, markdown content structure, dependency management, and description clarity. This ensures your custom tools are functional and adhere to best practices.

No dependencies are required to build a custom tool with Claude skills. The system guides you through authoring the SKILL.md file from scratch, covering YAML frontmatter syntax and markdown content structure without relying on external libraries or frameworks.