Writing Instructions for Claude

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

Overlap notice. crafting-instructions carries the same five core principles and a fuller format-decision framework. The two were written independently and never reconciled; a 2026-08-24 retrieval measurement put their descriptions at 0.843 cosine, the most confusable pair in the 92-skill catalogue. Until they are merged, this skill owns writing quality and crafting-instructions owns the format decision.

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.