Use when writing skills, CLAUDE.md files, agent prompts, or any code/directive that involves shell commands, environment variables, API credentials, file creation, or git operations - prevents secrets leakage into LLM context, unsafe shell patterns, and credential exposure.
Use when writing or revising any instruction Claude will read - skills, CLAUDE.md files, agent prompts, system prompts, hook output. Covers token efficiency, compliance techniques, discovery, and per-format templates.
An independent advisor you shell out to for a second opinion. Use when planning complex changes, debugging across multiple files, making architecture decisions, reviewing your own work, or when a different perspective would help.
Drives the user's running Chrome via the Playwriter CLI. Use when the task needs their browser identity — cookies, logins, open tabs, profile.
Review changed code for reuse, quality, and efficiency, then fix any issues found.