Build Skills That Extend Claude

Provides structured guidance for creating reusable skills that extend Claude with specialized knowledge, workflows, and tool integrations. Skills package information into three layers (metadata, SKILL.md instructions, bundled resources) using progressive disclosure to keep context efficient while maintaining deep expertise. It covers the entire skill lifecycle: understanding use cases, planning contents, initializing structure, implementing resources, and packaging for distribution.

Follow a six-step process: 1. Understand the skill through concrete use-case examples. 2. Plan reusable contents (scripts, references, assets) by analyzing each example. 3. Initialize the skill directory with init_skill.py, which generates a template. 4. Edit the skill by implementing resources and writing clear SKILL.md instructions. 5. Package the skill with package_skill.py, which validates structure and creates a distributable file. 6. Iterate based on real usage feedback. Output: A packaged .skill file with metadata for triggering, concise SKILL.md instructions, and bundled resources that other instances of Claude can use immediately.

Skills use YAML frontmatter (name, description) to trigger and can include Python, Bash, or other executables in scripts/. References files support Markdown. Assets can be any file type. Avoid deeply nested references. For large files (>100 lines), include a table of contents. No separate README.md or documentation files; only include what's necessary for Claude to execute the skill.