agent-arena

Use when the user asks for a second opinion, independent/heterogeneous review, architecture red-team, cross-model critique (Codex/Claude/GLM/DeepSeek/Qwen/Kimi), review my plan, challenge this design, evidence-checked code/PR review, or multi-agent critique of a high-stakes plan, design, research claim, or bug root-cause. Not for simple lookups, formatting, or low-stakes tasks. On error_max_turns before any answer: mechanical failure, not a result — check if you boxed an open design review (needs broad read-only tools + ample turns) as bounded verification; retry ONCE with lossless moves only. Disabling the reviewer's tools, feeding excerpts, or narrowing scope are LOSSY — never automatic; STOP and ask the user. Keep packet AND output on disk (stage packet via stdin, redirect claude -p output to a file); read back only a structured digest preserving dissent, never the raw JSON; checkpoint each round to disk — else the prompt+output inflate your context, trigger compaction, and loop into re-running arena.

Use when comparing non-trivial options or making a design/architecture/experiment/product/research/strategy decision with real tradeoffs, unclear criteria, or commitment risk, and the user says things like "比较一下 A 和 B", "还有别的方案吗", "方案的利弊/权衡是什么", "这样设计好不好", "换个角度", "深入分析", "review my plan", "compare A vs B vs A+B", "what are the alternatives", "what are the tradeoffs", "is this the right approach", or "think this through". Also self-trigger when you only have A/B/A+B, the options are minor variants, success criteria or flip conditions are unclear, or one hidden assumption is deciding the answer; expand the option space and challenge the framing before choosing. Escalate to agent-arena when external evidence or an independent reviewer is needed. Not for simple lookups, formatting, translation, trivial naming/style choices, routine code review without design uncertainty, or when the user asked for a fast answer.