agent-skills: Instructions file for Codex

AGENTS.md

agent-skills AGENTS.md is an instructions file for Codex, OpenCode from PaulRBerg/agent-skills. It costs 2,004 tokens per session, scanned A, original, MIT.

A set of instructions for coding agents that explains how to create agent skills, improve prompts, communicate with users, and report evidence. It is part of the PaulRBerg/agent-skills collection for Claude Code, Codex, and similar tools.

In plain words
What is it for?
Use it when maintaining agent skills, optimizing instructions, planning multi-step agent work, or deciding how to communicate progress and evidence.
Why use it?
It gives agents shared guidance for producing clear work and user-facing responses. It also helps them choose suitable models and handle complex tasks consistently.

Instructions file for CodexOpenCode

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

This is PaulRBerg/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 PaulRBerg/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/PaulRBerg/agent-skills/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/PaulRBerg/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/paulrberg/agent-skills/agents-md.svg)](https://agentmods.dev/instructions/paulrberg/agent-skills/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/paulrberg/agent-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/paulrberg/agent-skills/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,004 This file is loaded in full into every session.
When invoked 2,004 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 $0.02004 $0.02004
Opus 5 $0.01002 $0.01002
Sonnet 5 $0.00401 $0.00401
Haiku 4.5 $0.00200 $0.00200

Measured yesterday against content hash d2f9dfee1c3e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, 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 yesterday.

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 · 122 lines

How it starts

The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Skills

Collection of self-contained agent skills for Claude Code, Codex, and compatible agents. Keep README.md minimal and human-facing; put maintainer and agent guidance here.

Model Optimization

Optimize every skill and other agent-facing content for GPT-6 Astra and Claude Fable 5.1. The summaries below are reminders, not substitutes for the live guides. Read both guides before complex, long-running, multi-tool, or orchestration-heavy work because their recommendations may evolve.

  • GPT-6 Astra prompting guidance: Complete authorized work under stated assumptions; make user-instruction precedence over skills explicit; specify writing and delegation preferences; and keep verification proportional to the change.
  • Claude Fable 5.1 prompting guidance: Calibrate effort with evals; request progress updates; batch independent tool calls; preserve decisions across compaction; verify changing facts; and finish the requested scope with targeted edits and proportionate tests.

User-Facing Communication

Treat visual structure as information architecture, not decoration.

  • Use a small semantic status vocabulary consistently: 🔎 preview/read-only, running, verified success, ⚠️ caveat/approval/risk, blocked/not written, unknown, and reverted/rolled back. When a status icon is used, pair it with a status word; never make color or emoji the only carrier of meaning.
  • Lead reports with one outcome line. Use at most one non-status domain icon per heading for identity, then add compact headings for changed artifacts, verification, and risks only when those sections are useful.
  • Use tables for repeated fields, trees for real hierarchy or file structure, and progress bars only when a measured numerator and denominator exist. Never imply progress from elapsed time, activity, or guesswork.
  • Keep JSON, JSONL, DOT, CSV/TSV, exact commands, confirmation tokens, identifiers, addresses, hashes, signatures, diagnostics, logs, copied prompts, and other machine-consumed or verbatim content undecorated. Keep safety and rollback wording direct.
  • Decoration belongs to the agent's status wrapper. Do not add emoji or ASCII ornament to source code, generated artifacts, product UI copy, GitHub contributions, spreadsheet data, or user-authored content unless the task itself calls for it.

Read the full file on GitHub · 122 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. yesterday Changed · -2 lines · -6 tokens per session d2f9dfee1c3e
  2. 7d ago First seen · 124 lines · 2,010 tokens per session scan A a754865579a2

Subscribe to this mod's changes

agent-skills AGENTS.md is an instructions file published in the GitHub repository PaulRBerg/agent-skills (70 stars, last pushed 2d ago), licensed MIT. It adds 2,004 tokens to every session, about $0.0100 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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