agent-creator

agent-creator is a skill for Claude Code from coroboros/agent-skills. It costs 113 tokens per session (2,994 once invoked), scanned A, original, MIT.

A skill for creating and coordinating Claude Code subagents, which are separate agent instances assigned focused roles. It covers their instructions, available tools, permissions, hooks, and background work.

In plain words
What is it for?
Use it to define specialized subagents, configure their YAML settings, restrict their tools, design their prompts, and coordinate multi-agent workflows.
Why use it?
It helps divide complex coding tasks into smaller jobs with clear responsibilities and limited access.

Skill for Claude Code

Written for Claude Code: when-to-use in frontmatter. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions subagents.

Part of the claude-code-skills plugin — 2 skills shipped together

Good fit Use it to define specialized subagents, configure their YAML settings, restrict their…

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Install with agentmods
npx agentmods add skills/coroboros/agent-skills/agent-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 coroboros/agent-skills --skill agent-creator
Clone the repo
git clone --depth 1 https://github.com/coroboros/agent-skills

Made for: Claude Code.

Or install claude-code-skills, the plugin that ships this one along with the rest of its 2 skills.

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-creator

README.md
[![agentmods](https://agentmods.dev/badge/skills/coroboros/agent-skills/agent-creator.svg)](https://agentmods.dev/skills/coroboros/agent-skills/agent-creator)
Your own site
<a href="https://agentmods.dev/skills/coroboros/agent-skills/agent-creator"><img src="https://agentmods.dev/badge/skills/coroboros/agent-skills/agent-creator.svg" alt="Measured on agentmods" height="20"></a>
Per session 113 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,994 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00113 $0.02994
Opus 5 $0.00056 $0.01497
Sonnet 5 $0.00023 $0.00599
Haiku 4.5 $0.00011 $0.00299

Measured 6d ago against content hash a4b4b87fe323, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

agent-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 6d 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.

skills/agent-creator/SKILL.md · 224 lines

How it starts

The opening of the file, as written. The whole thing — 224 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Creator

Important — Writing rules

These rules govern every prose artifact this skill emits — READMEs, CHANGELOGs, commit messages, PR bodies, release notes, doc paragraphs, non-trivial comments. Apply them at draft time, verify before output.

  • Match the surrounding style — punctuation, capitalization, backtick conventions, em-dash vs parens, bullet style.
  • Every sentence changes the reader's understanding. Cut it otherwise.
  • Front-load the verb — "Creates", not "This helps you create".
  • Concrete over abstract. Lists for ≥3 enumerable items.
  • Assert positively. Reserve negation for real constraints (NEVER commit secrets).
  • No marketing words: powerful, robust, seamlessly, leverage, unlock, comprehensive, delightful.
  • No AI tells: delve, tapestry, intricate, pivotal, testament, underscore, crucial, garner, showcase, additionally, moreover, furthermore, indeed.
  • After drafting English prose, invoke /humanize-en if installed.

Subagents are specialized Claude instances that run in isolated contexts with focused roles and limited tool access. This skill covers how to create effective subagents, write strong system prompts, configure tool access, and orchestrate multi-agent workflows.

Subagents enable delegation of complex tasks to specialized agents that operate autonomously without user interaction, returning their final output to the main conversation.

Capture Intent

Before drafting an agent, surface the four contract questions. If the user's spec is vague, ask these via AskUserQuestion rather than fabricating answers:

  1. What should this agent do? — the specific task and role (e.g., "review TypeScript PRs for security regressions"), not a generic description.
  2. When should it be invoked? — trigger conditions, keywords, file patterns. Goes into the description field for routing.
  3. Which tools does it need? — least-privilege allowlist. Read-only analysis vs write-capable.
  4. What's the expected output format? — structured report, file edits, list of findings, etc.

Read the full file on GitHub · 224 lines

Files

What ships with it

8 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. 6d ago First seen · 224 lines · 113 tokens per session scan A a4b4b87fe323

Subscribe to this mod's changes

agent-creator is a skill published in the GitHub repository coroboros/agent-skills (4 stars, last pushed today), licensed MIT. It adds 113 tokens to every session and 2,994 once invoked, about $0.0006 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.