host-instruction-drift-checker

name	host-instruction-drift-checker
description	Check whether host instruction surfaces such as AGENTS.md, CLAUDE.md, Codex agents, Cursor rules, Copilot instructions, and SKILL.md files have drifted apart.

Host Instruction Drift Checker

Use this skill when a repo supports multiple coding-agent hosts or when a baseline update may change agent behavior.

Process

• Identify the canonical instruction source for the repo.
• Inventory host surfaces:
  • AGENTS.md
  • CLAUDE.md
  • AGENT_INSTRUCTIONS.md
  • .claude/agents/*
  • .codex/agents/*
  • .agents/skills/*/SKILL.md
  • .claude/skills/*/SKILL.md
  • .codex/skills/*/SKILL.md
  • .cursor/rules/*.mdc
  • .github/copilot-instructions.md
• Compare only the behavioral contract: scope, permissions, stop rules, evidence, generated-file ownership, and profile/installer semantics.
• Treat host-specific syntax as normal, not drift.
• Classify each mismatch as generated drift, overlay drift, stale doctrine, policy conflict, missing host surface, or intentional host specialization.
• Prefer updating canonical source and regenerating derived surfaces over hand-editing generated agent files.

Output

Canonical Source

Surfaces Checked

Drift Findings

Intentional Differences

Regeneration Path

Required Manual Review

Avoid

• forcing every host file to contain identical prose
• editing generated files as if they were canonical
• ignoring Cursor .mdc and Copilot surfaces when the repo advertises those hosts
• treating missing evidence gates as minor wording drift