agent-creator

agent-creator is a skill for Claude Code, Codex from majiayu000/claude-skill-registry. It costs 87 tokens per session (1,336 once invoked), scanned A, original, MIT.

A guide for creating subagents, which are specialized assistants that another coding assistant can call for focused tasks.

In plain words
What is it for?
Use it to create plugin agents or project agents with clear capabilities and invocation rules.
Why use it?
It explains the different agent formats and required fields, preventing invalid definitions and misplaced configuration.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: reads .claude/ paths; mentions subagents; mentions Claude Code.

Good fit Use it to create plugin agents or project agents with clear capabilities and invocation rules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor
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 majiayu000/claude-skill-registry --skill agent-creator-basher83-agent-auditor
Clone the repo
git clone --depth 1 https://github.com/majiayu000/claude-skill-registry

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 agent-creator

README.md
[![agentmods](https://agentmods.dev/badge/skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor/github.svg)](https://agentmods.dev/skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor)
Your own site
<a href="https://agentmods.dev/skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor"><img src="https://agentmods.dev/badge/skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor/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 agent-creator

Your own site · 80×15
<a href="https://agentmods.dev/skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor"><img src="https://agentmods.dev/badge/skills/majiayu000/claude-skill-registry/agent-creator-basher83-agent-auditor.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 87 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,336 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Rogue Agent · line 4
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
How audits are shown
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 $0.00087 $0.01336
Opus 5 $0.00044 $0.00668
Sonnet 5 $0.00017 $0.00267
Haiku 4.5 $0.00009 $0.00134

Measured 8d ago against content hash d8cbfecf0378, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, 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 8d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/agent/agent-creator-basher83-agent-auditor/SKILL.md · 200 lines

How it starts

The opening of the file, as written. The whole thing — 200 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Creator

Overview

Creates subagent definitions for Claude Code. Subagents are specialized assistants that Claude can invoke for specific tasks.

When to use: User requests an agent, wants to add specialized subagent to plugin, or needs agent structure guidance.

References: Consult plugins/meta/claude-docs/skills/official-docs/reference/plugins-reference.md and plugins/meta/claude-docs/skills/official-docs/reference/sub-agents.md for specifications.

CRITICAL: Two Types of Agents

Claude Code has two distinct agent types with different requirements:

Plugin Agents (plugins/*/agents/)

Purpose: Agents distributed via plugins for team/community use

Required frontmatter fields:

  • description (required) - What this agent specializes in
  • capabilities (required) - Array of specific capabilities

Location: plugins/<category>/<plugin-name>/agents/agent-name.md

Example:

---
description: Expert code reviewer validating security and quality
capabilities: ["vulnerability detection", "code quality review", "best practices"]
---

User/Project Agents (.claude/agents/)

Purpose: Personal agents for individual workflows

Required frontmatter fields:

  • name (required) - Agent identifier
  • description (required) - When to invoke this agent
  • tools (optional) - Comma-separated tool list
  • model (optional) - Model alias (sonnet, opus, haiku)

Location: .claude/agents/agent-name.md or ~/.claude/agents/agent-name.md

Example:

---
name: code-reviewer
description: Expert code review. Use after code changes.
tools: Read, Grep, Glob, Bash
model: sonnet
---

Key difference: User agents have name field and system prompt. Plugin agents have capabilities array and documentation.

Agent Structure Requirements (Plugin Agents)

Every plugin agent MUST include:

  1. Frontmatter with description and capabilities array
  2. Agent title as h1
  3. Capabilities section explaining what agent does
  4. When to Use section with invocation criteria
  5. Context and Examples with concrete scenarios
  6. Located in agents/agent-name.md within plugin

Read the full file on GitHub · 200 lines

Files

What ships with it

1 file 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 · 200 lines · 87 tokens per session scan A d8cbfecf0378

Subscribe to this mod's changes

agent-creator is a skill published in the GitHub repository majiayu000/claude-skill-registry (604 stars, last pushed yesterday), licensed MIT. It adds 87 tokens to every session and 1,336 once invoked, about $0.0004 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 2026-09-03.