prompt-engineering

Writes, rewrites, reviews, and audits prompts and system prompts using Anthropic's current official guidance, and selects the right model and effort level for the task before drafting. Use when the user asks to write a prompt, improve or fix a prompt, design a system prompt, or check a prompt before running a task — including phrasings like "write me a prompt for", "make this prompt better", "design a system prompt", "check my prompt before I run this", "turn these requirements into a prompt". Applies whether the resulting prompt will be pasted into Claude Code for a coding task or run in a desktop chat or Cowork session for a non-coding task. Also use when the user pastes a prompt and asks why it is not working, when they are authoring an agent system prompt or CLAUDE.md, or when they ask which model or effort level to use. Several widely repeated prompt techniques are now obsolete or rejected by the API, so consult this skill even when prompting from memory feels sufficient.