skill-creator

skill-creator is a skill for Claude Code from yohey-w/multi-agent-shogun. It costs 128 tokens per session (3,537 once invoked), scanned B, original, MIT.

A guide for designing and creating Claude Code skills, which are reusable instruction packages for AI coding tools. It covers their structure, descriptions, activation rules, compatibility, and validation.

In plain words
What is it for?
Creating new skills, improving existing SKILL.md files, checking descriptions, defining trigger tests, and preparing skills for use beyond Claude Code.
Why use it?
It helps avoid skills that trigger at the wrong time, give unclear instructions, or are difficult to maintain across different AI tools.

Skill for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: reads .claude/ paths; positional $N argument; mentions Claude Code.

Good fit Creating new skills, improving existing SKILL.md files, checking descriptions, defining trigger tests…

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/yohey-w/multi-agent-shogun/skill-creator
About the project

multi-agent-shogun is a system that coordinates multiple AI coding command-line agents through a hierarchy of managers, strategists, and workers. Developers use it to split coding requests into parallel tasks and monitor their execution through tmux.

yohey-w/multi-agent-shogun · 1,420 stars · on GitHub

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 yohey-w/multi-agent-shogun --skill skill-creator
Clone the repo
git clone --depth 1 https://github.com/yohey-w/multi-agent-shogun

Made for: Claude Code.

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/yohey-w/multi-agent-shogun/skill-creator.svg)](https://agentmods.dev/skills/yohey-w/multi-agent-shogun/skill-creator)
Your own site
<a href="https://agentmods.dev/skills/yohey-w/multi-agent-shogun/skill-creator"><img src="https://agentmods.dev/badge/skills/yohey-w/multi-agent-shogun/skill-creator.svg" alt="Measured on agentmods" height="20"></a>
Per session 128 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,537 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. 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 $0.00128 $0.03537
Opus 5 $0.00064 $0.01768
Sonnet 5 $0.00026 $0.00707
Haiku 4.5 $0.00013 $0.00354

Measured 7d ago against content hash 2d828dd74475, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade B, and why

skill-creator scanned grade B with 1 finding 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 7d 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.

Enumerates other installed skillsmediumAgent snooping

Other skills' SKILL.md files reveal prompts, capabilities and secrets that should be invisible to peers.

4. **既存スキルとの重複チェック**: `ls ~/.claude/skills/` で確認
skills/skill-creator/SKILL.md · 275 lines

How it starts

The opening of the file, as written. The whole thing — 275 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Creator — Claude Code Skills Design & Generation v2.0

Anthropic公式 "The Complete Guide to Building Skills for Claude" (2026-03) に完全準拠。 Agent Skills Open Standard (agentskills.io) にも対応し、Claude Code以外のAIツールでも動作するスキルを設計する。

North Star

再利用可能で高品質なスキルを最短で設計・作成すること。 スキルの価値 = 発火精度 × 出力品質 × 保守性。

Frontmatter Reference(全フィールド)

---
# === 必須フィールド ===
name: skill-name              # kebab-case, max 64 chars. 省略時はディレクトリ名
                               # "claude" / "anthropic" を含む名前は禁止(予約語)
description: |                 # 【最重要】発火判断の唯一の材料。1024文字以内
  What + When を明記。トリガーワードを含める。
  ネガティブトリガー(Do NOT use for...)で誤発火防止。

# === 任意フィールド ===
argument-hint: "[target]"      # 補完時のヒント表示。引数ありスキル用
disable-model-invocation: false # true = 手動 /name でのみ起動(副作用あるスキル向け)
user-invocable: true           # false = /メニュー非表示(背景知識スキル向け)
allowed-tools: Read, Grep, Bash # 許可ツール。指定すると制限にもなる。省略=全ツール継承
model: sonnet                  # スキル実行時のモデル指定(省略=親から継承)
context: fork                  # fork = サブエージェントで隔離実行
agent: general-purpose         # fork時のエージェント種別: Explore, Plan, general-purpose
license: MIT                   # OSSスキル用。MIT, Apache-2.0 等
compatibility: |               # 環境要件(1-500文字)
  Claude Code + tmux + WSL2
metadata:                      # カスタムメタデータ
  author: your-name
  version: 1.0.0
  mcp-server: server-name      # MCP連携スキル用
hooks:                         # スキル内フック定義
  PostToolUse:
    - matcher: "Edit|Write"
      hooks:
        - type: command
          command: "./scripts/lint.sh"
---

Frontmatter セキュリティ制約

  • XML角括弧 < > 禁止(プロンプトインジェクション防止)
  • nameに "claude" / "anthropic" は使用禁止(予約語)
  • フロントマターはシステムプロンプト内に展開される → 悪意あるコンテンツは危険

Description設計(最重要 — 発火品質を決める)

descriptionはClaude Codeが「このスキルを使うか否か」を判断する唯一の材料。 本文は発火判定に使われない。1024文字以内

構造: [What] + [When] + [Negative trigger]

# Good — 具体的、トリガーあり、ネガティブトリガーあり
description: |
  Figmaデザインファイルを分析し、開発者向けハンドオフドキュメントを生成。
  .figファイルアップロード時、「デザインスペック」「コンポーネント文書」
  「デザインからコードへ」と言われた時に起動。
  Do NOT use for: 一般的な画像処理やUI設計(interface-designスキルを使え)。

# Bad — 曖昧、トリガーなし
description: ドキュメント処理

Read the full file on GitHub · 275 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. 7d ago First seen · 275 lines · 128 tokens per session scan B 2d828dd74475

Subscribe to this mod's changes

skill-creator is a skill published in the GitHub repository yohey-w/multi-agent-shogun (1,420 stars, last pushed 1mo ago), licensed MIT. It adds 128 tokens to every session and 3,537 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it B with 1 finding (enumerates other installed skills). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.