skill-creator

skill-creator is a skill for Claude Code, Codex from yunseo-kim/agent-toolbox. It costs 45 tokens per session (3,729 once invoked), scanned A, original, no licence file.

A guide for creating or updating skills that extend an AI coding agent with specialised knowledge, workflows, or tool connections.

In plain words
What is it for?
Use it when designing a new agent skill or revising an existing one.
Why use it?
It provides a defined way to package repeatable instructions for a particular kind of work.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it when designing a new agent skill or revising an existing one.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/yunseo-kim/agent-toolbox/skill-creator
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 yunseo-kim/agent-toolbox --skill skill-creator
Clone the repo
git clone --depth 1 https://github.com/yunseo-kim/agent-toolbox

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-creator

README.md
[![agentmods](https://agentmods.dev/badge/skills/yunseo-kim/agent-toolbox/skill-creator/github.svg)](https://agentmods.dev/skills/yunseo-kim/agent-toolbox/skill-creator)
Your own site
<a href="https://agentmods.dev/skills/yunseo-kim/agent-toolbox/skill-creator"><img src="https://agentmods.dev/badge/skills/yunseo-kim/agent-toolbox/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.

agentmods 80×15 button for skill-creator

Your own site · 80×15
<a href="https://agentmods.dev/skills/yunseo-kim/agent-toolbox/skill-creator"><img src="https://agentmods.dev/badge/skills/yunseo-kim/agent-toolbox/skill-creator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,729 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 unknown 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 $0.00045 $0.03729
Opus 5 $0.00023 $0.01865
Sonnet 5 $0.00009 $0.00746
Haiku 4.5 $0.00005 $0.00373

Measured 8d ago against content hash d57b6e3a4453, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, 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 8d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (scripts/init_skill.py, scripts/package_skill.py, scripts/quick_validate.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.

.agents/skills/skill-creator/SKILL.md · 358 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

6 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. 8d ago First seen · 358 lines · 45 tokens per session scan A d57b6e3a4453

Subscribe to this mod's changes

skill-creator is a skill published in the GitHub repository yunseo-kim/agent-toolbox (1 stars, last pushed yesterday), with no licence file. It adds 45 tokens to every session and 3,729 once invoked, about $0.0002 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.