What it does. Codex metadata for the skill: display name “Diagnosing Bugs” and short description “Diagnose hard bugs and regressions”. It has no policy block, so Codex may start the skill on its own.
Why it’s here. Codex reads it for its skill picker. The repo’s .agents/invocation.md says every skill carries one and that “It holds Codex UI metadata”. Leaving out the policy block keeps the skill model-invoked, matching its SKILL.md. SKILL.md itself does not refer to this file.