Use when the current session needs an answer or a work product from a model on ANOTHER vendor's stack - a second opinion from a different model family, a cheap fast model for bulk work, or a cross-model review - by dispatching that vendor's own CLI as a one-shot worker. Triggers include "ask grok/composer/gemini/claude/codex what it thinks", "get a second opinion from a different model", "cross-model review", "run this by another model", "poll several models". No orchestration framework required; if a Brigade roster exists, prefer `brigade run --worker` instead.
Use when setting up, checking, writing, linting, or troubleshooting Brigade memory handoffs for a repo or agent workspace, especially when a user wants durable agent memory, handoff inboxes, cross-harness memory routing, or a safe first Brigade setup.
Use when asked to find bugs, hunt for correctness issues, sweep a codebase for defects, or verify a repo behaves as intended. Not for style or architecture review; this is defect-finding only.
Use when about to claim anything works, is fixed, is complete, or passes - before committing, replying to the user, or moving to the next task. Also use when relaying a subagent's or tool's success report, and especially at the end of a long session when the pull to say "done" is strongest.
Use before implementing, scaffolding, prototyping, or adding a feature when the work should start with the smallest useful code path, avoid speculative architecture, or prevent overbuilding before reduce would be needed.
Use when the user wants to act on an audit, fix the findings in a line-check/bug-hunt/security-sweep report, work a prioritized backlog, or asks to "fix the findings", "work the backlog", "clear the audit", or "do the high-leverage items". The step after the audit trio.
Use when a written implementation plan is ready to execute, when the user says "fire", "execute the plan", "build it", or hands over a plan file to implement. The step after recipe.
Use when auditing or fixing discoverability metadata for a website before publication, including titles, descriptions, canonical URLs, robots policy, Open Graph, structured data, and sitemaps. Not for content strategy or keyword research.