Intro to Claude Code Skills

Learn what Claude Code Skills are, how they work, and why they're the recommended way to extend Claude Code's capabilities. This lesson covers the essential concepts — where Skills live, how they're structured, and the invocation model that lets Claude discover and use them automatically or lets you trigger them manually with a slash command.

From the folder structure of a Skill to the critical role of the description field in auto-discovery, you'll understand everything you need before building your first custom Skill. You'll also learn how Skills differ from the older custom commands system and why Skills are more powerful and context-efficient.

• What Skills are and why Anthropic is unifying everything under Skills
• The folder structure: SKILL.md plus optional scripts, references, and supporting files
• Personal Skills (~/.claude/skills/) vs Project Skills (.claude/skills/)
• How auto-discovery works through description matching
• Controlling invocation with disable-model-invocation and user-invocable
• How Skills stay context-efficient — content only loads when a Skill is actually invoked
• The relationship between Skills and the older custom commands system