Validating Your CLAUDE.md: A Benchmarking Tool to Measure Agent Performance Impact

Most CLAUDE.md files are written blindly and may increase agent costs by 20%+ while reducing effectiveness. mdarena benchmarks different CLAUDE.md approaches against real PRs and test suites, replacing guesswork with data-driven validation. The key insight: strategic context placement beats comprehensive documentation, with poorly-designed consolidated files performing worse than no context.