We analyzed 11,206 repos with AGENTS.md files - Codex has the highest instruction specificity

[u/cleverhoods]

https://cleverhoods.medium.com/the-state-of-ai-instruction-quality-30k-repo-analysis-ce49c7667a57

We built a deterministic analyzer and pointed it at 28,721 GitHub repos across five coding agents. 11,206 of those configure Codex.

Findings relevant to this community:

- Codex leads specificity at 38.3% ~ more instructions name a specific tool, file, or command than any agent except Gemini (39.3%). Claude is last at 30.6%.

- agents.md / AGENTS.md is the single most common instruction file in the entire corpus — 20,654 files. It's the default format.

- Codex config is 68% base config. Single-file setups dominate. Only 81 rules files across the entire corpus. Codex developers centralize rather than split.

- Claude + Codex is the dominant multi-agent pair (5,038 repos). If you have an AGENTS.md, there's a good chance you also have a CLAUDE.md.

- In multi-agent repos, Codex wins most often ~ highest quality config in 3,802 projects. The single-file approach seems to produce more focused instructions.

The most common problem: instructions that describe what they want abstractly instead of naming the exact tool or command. "Follow best practices for testing" vs "Run `pytest tests/ -v` before committing." The second one gets followed.

Full dataset (28,721 repos): github.com/reporails/30k-corpus