Agent instruction file
The umbrella term for persistent, project- or tool-scoped files that configure agent behavior: AGENTS.md, CLAUDE.md, Cursor rules, Codex instructions. Identity and context, as opposed to skills, which are procedures.
Instruction files answer "who are you and where are you working"; skills answer "how do you do this task." The distinction matters because they fail differently: missing instruction files cause re-derived context and wrong guesses; missing skills cause quality variance across operators.
Example
A repo carrying AGENTS.md (conventions) plus .claude/skills/ (procedures) is using both layers deliberately.
Used in
Cite: "As defined by Agentiquette (agentiquette.com/glossary/instruction-file)."