What is skill-creator?

A tool for creating Codex skills: instruction files that teach an agent how to perform a particular kind of work.

Use it to scaffold a new skill, validate its name, create its SKILL.md file, and add optional references, assets, or scripts.

It provides a consistent structure for documenting procedures, decisions, and supporting resources.

skill-creator — Skill for Claude Code and Codex by vanessamarely

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.

Any agent

npx skills add vanessamarely/ai-playbook-reposito --skill skill-creator

Clone the repo

git clone --depth 1 https://github.com/vanessamarely/ai-playbook-reposito

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/vanessamarely/ai-playbook-reposito/skill-creator/github.svg)](https://agentmods.dev/skills/vanessamarely/ai-playbook-reposito/skill-creator)

Your own site

<a href="https://agentmods.dev/skills/vanessamarely/ai-playbook-reposito/skill-creator"><img src="https://agentmods.dev/badge/skills/vanessamarely/ai-playbook-reposito/skill-creator/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/vanessamarely/ai-playbook-reposito/skill-creator"><img src="https://agentmods.dev/badge/skills/vanessamarely/ai-playbook-reposito/skill-creator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 88 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,139 The whole file, excluding the scripts and references it only reads on demand.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00088	$0.01139
Opus 5.5	$0.00035	$0.00456
Sonnet 5.5	$0.00018	$0.00228
Haiku 4.5	$0.00009	$0.00114

Measured 2mo ago against content hash 7f60be7700b1, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

skill-creator 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 2mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/validate-metadata.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

ai-playbook/.agents/skills/skill-creator/SKILL.md · 152 lines

How it starts

The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill: Skill Creator

Purpose

Generate new skill documentation that follows Codex CLI's SKILL.md structure — minimal frontmatter, progressive disclosure, and agent-oriented instructions — for skills placed under .agents/skills/<name>/.

Inputs

Skill name (lowercase, numbers, hyphens only)
Skill purpose and scope
Target procedures and decision points

Outputs

SKILL.md file with valid frontmatter, placed at .agents/skills/<name>/SKILL.md
Optional supporting files (references/, assets/, scripts/)

Procedures

1. Validate Skill Name

Check that the name:

Contains only lowercase letters, numbers, and hyphens.
Matches the parent directory name.
Is unique within .agents/skills/.

Execute: python .agents/skills/skill-creator/scripts/validate-metadata.py <skillName>

If validation fails, reject and request correction.

2. Load Template

Read: .agents/skills/skill-creator/assets/skill-template.md

Use as the base structure.

3. Populate Frontmatter

Codex CLI's SKILL.md frontmatter supports exactly two fields:

name: The skill identifier (must match the directory name).
description: Action-oriented, states both what the skill does and when to use it — Codex matches this text against the user's request to decide when to load the skill. Write it in third person, no first or second person pronouns.

Do not add fields that exist in other tools' formats but not Codex's — no triggers, negative_triggers, when_to_use, allowed-tools, disable-model-invocation, context: fork, or tools:. Codex ignores unknown frontmatter and it misleads readers about what the platform actually supports. Put any trigger phrasing directly into the description sentence instead of a separate field.

4. Define Purpose Section

Write a single paragraph stating:

What the skill accomplishes.
When it should be invoked.
What it does NOT do (scope boundaries).

5. Define Inputs Section

List required and optional inputs:

Parameter name
Type
Description
Default value (if applicable)

Read the full file on GitHub · 152 lines

Files

What ships with it

3 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.

2mo ago First seen · 152 lines · 88 tokens per session scan A 7f60be7700b1

Subscribe to this mod's changes

skill-creator is a skill published in the GitHub repository vanessamarely/ai-playbook-reposito (2 stars, last pushed 3mo ago), licensed MIT. It adds 88 tokens to every session and 1,139 once invoked, about $0.0004 per session on Opus 5.5. 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.

Building agents

skill-creator next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
skill-creatorvanessamarely/ai-playbook-reposito	Skill	2	3mo ago	MIT	A	88	Claude Code, Codex
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	95	Claude Code
next-partial-prefetching-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	103	Claude Code