Cross-model critique

A second pair of eyes from a non-Claude model (Codex) on a proposal Claude just made — a design, refactor, API, or fix. Goal: a genuine cross-model check. Validate what holds up, challenge what is weak, surface a better path when one exists. Not a rubber stamp, not reflexive contrarianism.

When to use

• Claude (this instance or another) proposed a solution and you want it pressure-tested before committing.
• You said "not bad, right?" and actually want the honest answer.
• A decision has real forks and one outside viewpoint would de-risk it.

NOT for reviewing committed code against a diff — use /codex:review or /codex:adversarial-review. Those read the git diff; a proposal usually lives in the conversation, not on disk, so a diff-based review would miss it (and may review unrelated working-tree files instead).