agent-skills: Instructions file for Codex

AGENTS.md

agent-skills AGENTS.md is an instructions file for Codex, OpenCode from specstoryai/agent-skills. It costs 1,414 tokens per session, scanned A, original, Apache-2.0.

A repository of Agent Skills, which are instruction packages that give AI agents repeatable ways to handle particular tasks.

In plain words
What is it for?
It supports developing and checking skills, including validating their metadata and testing associated Python scripts.
Why use it?
It helps keep agent instructions, scripts, naming rules, and checks organised in one consistent format.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: mentions Claude Code; mentions AGENTS.md.

This is specstoryai/agent-skills's own configuration. It tells Codex and OpenCode how to work on agent-skills itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agent-skills configures →

Reuse

Borrowing it

Nothing to install: this file belongs to specstoryai/agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/specstoryai/agent-skills/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/specstoryai/agent-skills

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for agent-skills AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/specstoryai/agent-skills/agents-md.svg)](https://agentmods.dev/instructions/specstoryai/agent-skills/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/specstoryai/agent-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/specstoryai/agent-skills/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,414 This file is loaded in full into every session.
When invoked 1,414 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.01414 $0.01414
Opus 5 $0.00707 $0.00707
Sonnet 5 $0.00283 $0.00283
Haiku 4.5 $0.00141 $0.00141

Measured 8d ago against content hash 3002f8312f00, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

agent-skills 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 8d 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.

AGENTS.md · 189 lines

How it starts

The opening of the file, as written. The whole thing — 189 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Guidelines for AI agents working in this repository.

Repository Overview

This repository contains Agent Skills for AI agents following the Agent Skills specification.

Repository Structure

agent-skills/
├── skills/                # Agent Skills
│   └── specstory-*/
│       ├── SKILL.md       # Required skill file
│       ├── scripts/       # Optional Python scripts
│       └── LICENSE.txt    # Apache 2.0 license
├── LICENSE
└── README.md

Build / Lint / Test Commands

Skills with Python scripts can be tested with:

# Test yak shave analyzer
python skills/specstory-yak/scripts/analyze.py --help

# Test link trail parser
python skills/specstory-link-trail/parse_webfetch.py --help

Verify skill files manually:

  • YAML frontmatter is valid
  • name field matches directory name exactly
  • name is 1-64 chars, lowercase alphanumeric and hyphens only
  • description is 1-1024 characters

Agent Skills Specification

Skills follow the Agent Skills spec.

Required Frontmatter

---
name: specstory-skill-name
description: What this skill does and when to use it. Include trigger phrases.
license: Apache-2.0
metadata:
  author: SpecStory
  version: "1.0.0"
---

Frontmatter Field Constraints

Field Required Constraints
name Yes 1-64 chars, lowercase a-z, numbers, hyphens. Must match dir.
description Yes 1-1024 chars. Describe what it does and when to use it.
license No License name (default: Apache-2.0 for this repo)
metadata No Key-value pairs (author, version, etc.)

Read the full file on GitHub · 189 lines

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. 8d ago First seen · 189 lines · 1,414 tokens per session scan A 3002f8312f00

Subscribe to this mod's changes

agent-skills AGENTS.md is an instructions file published in the GitHub repository specstoryai/agent-skills (35 stars, last pushed 7mo ago), licensed Apache-2.0. It adds 1,414 tokens to every session, about $0.0071 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.

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