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.
npx agentmods add skills/gzupark/claude-plugin-pack/subagent-creatornpx skills add GzuPark/claude-plugin-pack --skill subagent-creatorgit clone --depth 1 https://github.com/GzuPark/claude-plugin-packWrote 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.
[](https://agentmods.dev/skills/gzupark/claude-plugin-pack/subagent-creator)<a href="https://agentmods.dev/skills/gzupark/claude-plugin-pack/subagent-creator"><img src="https://agentmods.dev/badge/skills/gzupark/claude-plugin-pack/subagent-creator.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00040 | $0.01406 |
| Opus 5 | $0.00020 | $0.00703 |
| Sonnet 5 | $0.00008 | $0.00281 |
| Haiku 4.5 | $0.00004 | $0.00141 |
Grade A, and why
subagent-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.
How it starts
The opening of the file, as written. The whole thing — 196 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Sub-agent Creator
Create specialized AI sub-agents for Claude Code that handle specific tasks with customized prompts and tool access.
Sub-agent File Format
Sub-agents are Markdown files with YAML frontmatter stored in:
- Project:
.claude/agents/(higher priority) - User:
~/.claude/agents/(lower priority)
Structure
---
name: subagent-name
description: When to use (include "use proactively" for auto-delegation)
tools: Tool1, Tool2, Tool3 # Optional - inherits all if omitted
model: sonnet # Optional - sonnet/opus/haiku/inherit
permissionMode: default # Optional - default/acceptEdits/plan
skills: skill1, skill2 # Optional - auto-load skills
---
System prompt goes here. Define role, responsibilities, and behavior.
Configuration Fields
| Field | Required | Description |
|---|---|---|
name |
Yes | Lowercase with hyphens |
description |
Yes | Purpose and when to use (key trigger) |
tools |
No | Comma-separated tool list |
model |
No | sonnet, opus, haiku, or inherit |
permissionMode |
No | default, acceptEdits, plan, etc. |
skills |
No | Skills to auto-load |
hooks |
No | Hooks for lifecycle (PreToolUse, etc.) |
Creation Workflow
- Gather requirements: Ask about purpose, when to use, and capabilities
- Choose scope: Project (
.claude/agents/) or user (~/.claude/agents/) - Define configuration: Name, description, tools, model
- Write system prompt: Clear role, responsibilities, and output format
- Create file: Write the
.mdfile to the appropriate location
Writing Effective Sub-agents
Description Best Practices
The description field is critical for automatic delegation:
# Good - specific triggers
description: Expert code reviewer. Use PROACTIVELY after writing code.
# Good - clear use cases
description: Debugging specialist for errors, test failures, unexpected behavior.
# Bad - too vague
description: Helps with code
What ships with it
4 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.
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.
- 6d ago First seen · 196 lines · 40 tokens per session scan A 85213132b00d
subagent-creator is a skill published in the GitHub repository GzuPark/claude-plugin-pack (6 stars, last pushed 7mo ago), licensed MIT. It adds 40 tokens to every session and 1,406 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.
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