skill-authoring

skill-authoring is a skill for Claude Code, Codex from YankielDBC2/codex-skills-library. It costs 26 tokens per session (312 once invoked), scanned A, original, MIT.

A set of instructions for creating and maintaining Codex skills, which are reusable instructions that guide an AI coding agent through a specific job.

In plain words
What is it for?
Use it to create, improve, review, document, or combine skills, then validate the skill library.
Why use it?
It helps keep skills focused, discoverable, testable, and free from unnecessary overlap.

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/yankieldbc2/codex-skills-library/skill-authoring
Any agent
npx skills add YankielDBC2/codex-skills-library --skill skill-authoring
Clone the repo
git clone --depth 1 https://github.com/YankielDBC2/codex-skills-library

Made for: Claude Code, Codex.

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 skill-authoring

README.md
[![agentmods](https://agentmods.dev/badge/skills/yankieldbc2/codex-skills-library/skill-authoring.svg)](https://agentmods.dev/skills/yankieldbc2/codex-skills-library/skill-authoring)
Your own site
<a href="https://agentmods.dev/skills/yankieldbc2/codex-skills-library/skill-authoring"><img src="https://agentmods.dev/badge/skills/yankieldbc2/codex-skills-library/skill-authoring.svg" alt="Measured on agentmods" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 312 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 5.1 $0.00026 $0.00312
Opus 5 $0.00013 $0.00156
Sonnet 5 $0.00005 $0.00062
Haiku 4.5 $0.00003 $0.00031

Measured 5d ago against content hash 0cd6f9d371e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

skill-authoring 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 5d 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/skills/skill-authoring/SKILL.md · 49 lines

What it actually says

Skill Authoring

Goal

Create high-quality skills that Codex can discover and apply reliably.

When to use

Use when adding a new skill, improving an existing skill, reviewing skill quality, creating references, or deduplicating overlapping skills.

When not to use

Do not use for normal product implementation unless the task is to update the skill library itself.

Inputs

Inspect the proposed skill purpose, existing similar skills, docs/SKILL_SPEC.md, docs/STYLE_GUIDE.md, and docs/QUALITY_RUBRIC.md.

Workflow

  1. Define the single job of the skill.
  2. Search for overlapping skills before creating a new one.
  3. Write precise activation frontmatter.
  4. Put the durable process in SKILL.md.
  5. Move long examples to references/.
  6. Add scripts only for deterministic checks.
  7. Run validation and duplicate checks.
  8. Generate the catalog after changes.

Quality bar

A good skill is narrow, discoverable, safe, testable, and easy to maintain.

Validation

Run npm run validate, npm test, and npm run catalog.

Final response

Report the skill created or changed, why it is not duplicated, validation output, and any future improvement ideas.

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. 5d ago First seen · 49 lines · 26 tokens per session scan A 0cd6f9d371e1

Subscribe to this mod's changes

skill-authoring is a skill published in the GitHub repository YankielDBC2/codex-skills-library (10 stars, last pushed 1mo ago), licensed MIT. It adds 26 tokens to every session and 312 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 2026-08-31.