Skill vs prompt

A prompt is a one-off instruction you type; it applies to that turn and is gone. A skill is a prompt you got tired of retyping, saved as a SKILL.md file, with a description that lets Claude load it on its own when relevant. The official documentation suggests creating a skill when you keep pasting the same instructions, checklist, or multi-step procedure into chat.

The distinction is most useful when considering the three contexts Claude Code operates within:

• Prompt: A single instruction for the current turn. It costs nothing when unused and is gone after the turn.
• CLAUDE.md: This file is loaded into every session at start. It should contain context Claude should always know, such as build commands, project conventions, layout, or rules like 'always do X'. To keep it efficient, it should stay under about 200 lines.
• Skill: Loaded on demand. Skills are best suited for procedures, checklists, or long reference material that only matter sometimes. The documentation explicitly states that if an entry in CLAUDE.md represents a multi-step procedure or is only relevant to a specific part of the codebase, it should be moved to a skill or a path-scoped rule.

None of these are enforcement layers; they all provide context that Claude reads and attempts to follow. For actions that must occur regardless of Claude's decision, you would use hooks.

Consider Authoring Skills for guidance on structuring your skills effectively. If you find yourself repeatedly typing the same prompt, it's a strong signal that a skill might be appropriate, rather than relying on ad-hoc prompts or cluttering your CLAUDE.md.