Practice — Multi-Agent Orchestration (5 questions)

A product manager asks you to design "an agent that reviews a pull request and leaves comments." A colleague's first sketch: a supervisor agent that spawns five parallel review agents (correctness, security, performance, style, test coverage), plus a synthesis agent that merges their comments — six agent invocations per PR.

1. Before accepting or rejecting that design, what questions do you ask to determine whether it's justified?
2. Give a rough cost comparison (in agent-invocations or token terms) between the six-agent design and one agent reviewing the PR end to end.
3. Under what conditions is the six-agent design actually the right call, and under what conditions would you push back and recommend a single stronger-model pass instead?