Comprehensive guide for creating modular skills that extend Claude's capabilities with specialized knowledge and workflows.

• Skills consist of a required SKILL.md file with YAML frontmatter and markdown instructions, plus optional bundled resources (scripts, references, assets) organized by purpose and loaded progressively to conserve context
• Design skills around concrete usage examples; identify reusable scripts for deterministic tasks, reference files for domain knowledge, and assets for output templates
• Keep SKILL.md concise by moving detailed information to separate reference files, using high freedom (text instructions) for flexible tasks and low freedom (specific scripts) for fragile operations
• Use the init_skill.py script to scaffold new skills, then implement resources, write clear triggering descriptions in frontmatter, and package with package_skill.py for distribution
• Iterate based on real usage; refine SKILL.md and resources when users encounter struggles or inefficiencies