validate-agents-md

A checker for AGENTS.md files, which are repository instructions for coding agents. It reviews their structure, operating rules, neutrality, and fit with the repository.

In plain words
What is it for?
Use it when adding, changing, or reviewing root or nested AGENTS.md files, including checks for version markers, paths, and required policy sections.
Why use it?
It helps find incomplete or outdated agent instructions before they cause inconsistent work or conflict with the project’s layout and rules.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/msiccdev/ai-context-kit/validate-agents-md
Any agent
npx skills add MSiccDev/ai-context-kit --skill validate-agents-md
Clone the repo
git clone --depth 1 https://github.com/MSiccDev/ai-context-kit

Made for: Claude Code, Codex.

Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 535 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00024 $0.00535
Opus 5 $0.00012 $0.00267
Sonnet 5 $0.00005 $0.00107
Haiku 4.5 $0.00002 $0.00053

Measured 2d ago against content hash a5ebab835f45, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

validate-agents-md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/validate-agents-md/SKILL.md · 57 lines

How it starts

The opening of the file, as written. The whole thing — 57 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Validate AGENTS.md

Purpose

Validate AGENTS.md files to ensure they are concise, operationally complete, and aligned with repository structure and governance.

When To Use

  • Use this skill when adding or updating root or nested AGENTS.md files.
  • Use this skill before accepting AGENTS policy changes.
  • Do not use this skill for user/project instruction validation.

How to Invoke

Load or attach this file's contents into your AI session to activate the workflow (paste, upload, or reference with #file:skills/validate-agents-md/SKILL.md in VS Code Copilot Chat). In Claude Projects, add it to project knowledge. See Invoking Skills in the README for full platform guidance.

Required Inputs

  • Target AGENTS.md path.
  • Repository path context for link/path validation.
  • Policy expectations for session-state and command namespace.

Workflow

  1. Run validation phases from references/phase-checks.md.
  2. Check for <!-- spec_version: ... --> comment: flag as WARNING if absent (pre-existing files may predate this requirement); flag as WARNING if present but older than 1.4.3.
  3. Generate report using references/report-contract.md.
  4. Apply deterministic scoring from references/scoring.md.
  5. Classify findings into critical/warning/enhancement buckets.
  6. Provide concrete fixes for operational contract gaps.

Output Expectations

  • Structured markdown report with five validation phases.
  • Compliance score and pass band.
  • Explicit list of critical issues, warnings, and enhancements.
  • Example fixes for common structural and policy failures.
  • Report schema follows references/report-contract.md.
  • Scoring and grade bands follow references/scoring.md.

Resources

  • Phase checks: references/phase-checks.md
  • Report contract: references/report-contract.md
  • Scoring model: references/scoring.md
  • Example target: ../../AGENTS.md

Constraints And Safety

  • Keep the scoring rubric deterministic; findings should be repository-specific and actionable.
  • Avoid over-prescriptive style-only feedback.
  • Preserve provider-neutral language.
  • Do not duplicate full normative specs when suggesting fixes.

Read the full file on GitHub · 57 lines

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 57 lines · 24 tokens per session scan A a5ebab835f45

Subscribe to this mod's changes

validate-agents-md is a skill published in the GitHub repository MSiccDev/ai-context-kit (12 stars, last pushed 4d ago), licensed MIT. It adds 24 tokens to every session and 535 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.