Writing Instructions for Claude

Principles and patterns for writing instructions that Claude follows reliably — whether as project instructions, standalone prompts, or skill content.

Choosing the Right Format

Determine format before writing. The wrong container undermines good instructions.

Project instructions — persistent context for a workspace. Use when all conversations in a project need shared knowledge, team collaboration context, or initiative-specific behavior. Signals: "for this project," "all conversations about X," "team workspace." Read references/project-instructions.md for detailed guidance.

Standalone prompts — ephemeral, conversational, immediate. Use for one-off requests, ad-hoc direction, or conversational refinement. Signals: "for this task," "right now," "just this once." Read references/standalone-prompts.md for techniques.

Skill content — portable expertise that loads on-demand across contexts. Use when capability is needed across multiple projects, procedural knowledge applies broadly, and instructions should activate automatically on relevant triggers. Signals: "every time I," "whenever," "reusable," "teach Claude how to." For building full skills (structure, testing, iteration, packaging), use the skill-creator skill.

Combined approaches work well: project instructions provide "what you need to know" (reference material, context) while skills provide "how to do things" (methods, procedures). Read references/choosing-formats.md for detailed comparison and migration patterns.