## Coordinated documentation The Claude and Codex README of each plugin share their product narrative, headings, order, common outcomes and decorative branding. Change common content in both editions together. Only the six bounded native exceptions may differ: identity, installation, commands, compatibility and actual availability, benchmarks, and edition-specific links. Main headings stay outside exceptions. Benchmark questions and columns stay the same. Results identify the actual host, model, source and date. Preserve negative results and limits. Never relabel a Claude measurement as Codex evidence, infer performance from unit tests, or fill missing results with invented values. Use `Not measured` and state when an edition is unavailable. Keep research and extensive methodology in Foundry documentation; keep usage guides and plugin-specific decisions with their plugin. When working in Foundry, use its `coordinate-readmes` skill for paired README changes and benchmark updates. Run `node scripts/git-hooks/check-readme-parity.js --check README.md --expect Codex` and `check-readme-nav.js` before considering the change ready. For committed revisions use `--git-pair `. Also inspect the original evidence: parser success is not proof of measurement quality. Both native review agents use the Foundry README template and the same review criteria. Platform-specific skills, rules and CI must keep this policy aligned. Foundry hosts both platforms; its plugin-only platform-isolation rule does not apply to the parent repository. ## Benchmark ownership Benchmark runners, datasets, measurement tests and experiments for this collection live in the Foundry benchmarks// directory. Keep functional product tests here; do not recreate a benchmarks/ or .benchmarks/ tree in the plugin. Local maintenance output and backups belong in the Foundry .scratch/ directory. Common README changes in separate platform PRs use the reciprocal PR/SHA protocol in `.github/README_COORDINATION.md`. A candidate-pair check does not replace the final integrated-branch comparison before selectors or pins publish.