# Host Instruction Drift Checker

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

- **Type:** Skill
- **Install:** `agentstack add skill-45ck-skill-harness-host-instruction-drift-checker`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [45ck](https://agentstack.voostack.com/s/45ck)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [45ck](https://github.com/45ck)
- **Source:** https://github.com/45ck/skill-harness/tree/main/packs/agent-operating-skills/skills/host-instruction-drift-checker
- **Website:** https://github.com/45ck/skill-harness/releases/tag/v0.1.0

## Install

```sh
agentstack add skill-45ck-skill-harness-host-instruction-drift-checker
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# 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

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [45ck](https://github.com/45ck)
- **Source:** [45ck/skill-harness](https://github.com/45ck/skill-harness)
- **License:** MIT
- **Homepage:** https://github.com/45ck/skill-harness/releases/tag/v0.1.0

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-45ck-skill-harness-host-instruction-drift-checker
- Seller: https://agentstack.voostack.com/s/45ck
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.