How to Answer
"Decision tree: ReAct when the task is exploratory and the path isn't known upfront (research, diagnosis). Planner-Executor when the task has clear phases and I want auditability — the plan is a human-readable artifact I can approve before execution. Great for compliance-heavy workflows. Multi-Agent only when there are genuinely separable domains of expertise — e.g., a researcher who searches the web and an analyst who runs SQL shouldn't share a context window. Multi-agent is a tool, not a default — it adds coordination overhead and debugging complexity."