write-subagent

name	write-subagent
description	Use when the user wants to create a new Claude Code subagent. Guides subagent creation with focused prompts and constrained tool access.

Subagent Creation Playbook

CRITICAL: Before deploying any subagent, spawn a reviewer agent with REVIEW.md to audit tools. Overly permissive tool access can cause data loss or leak secrets.

Create subagents as focused specialists, not general-purpose assistants.

Arguments

$ARGUMENTS

Process

0. Determine Scope

Check if arguments specify global or local:

• global or in ~/.claude/agents/ → Subagent goes in dotfiles via chezmoi, available everywhere
• local or in .claude/agents/ → Subagent goes in current project's .claude/agents/, scoped to this repo

If scope is unclear, ask:

"Should this subagent be global (available in all projects via dotfiles) or local (scoped to this project only)?"

1. No Arguments? Extract from Conversation

If arguments are empty, the user wants to codify a delegatable task:

1. Analyze the conversation for patterns that would benefit from isolated context
2. Identify: task type, tools needed, decision points, success criteria
3. Propose a subagent name and description based on what was done
4. Ask about scope (global vs local)
5. Draft the subagent with focused system prompt
6. Ask user to confirm or refine before writing

2. Gather Context (when args provided)

If unclear, ask:

• Primary task type?
• Tools needed? (prefer minimal set)
• Should it run in background? (noisy/long-running)
• Permission mode? (default/acceptEdits/dontAsk/plan)
• Skills to preload?

3. Draft Subagent

For global subagents: Create $(chezmoi source-path)/dot_claude/agents/<name>.md.tmpl (note .tmpl extension)

For local subagents: Create .claude/agents/<name>.md in the current working directory (plain .md, no template)

Global subagent template (.md.tmpl):

---
name: <kebab-case>
description: <When Claude should delegate + what it does. Use "proactively" for auto-use.>
tools: <minimal subset - see REVIEW.md>
disallowedTools: <explicit denials if inheriting>
{{ "{{-" }} template "bedrock-model" (dict "tier" "<haiku|sonnet|opus>" "root" .) {{ "}}" }}
permissionMode: <default|acceptEdits|dontAsk|plan>
skills: <list of skills to preload>
hooks: <optional lifecycle hooks>
---

<System prompt: Who the subagent is, what it does,   

Local subagent template (plain .md):

---
name: <kebab-case>
description: <When Claude should delegate + what it does. Use "proactively" for auto-use.>
tools: <minimal subset - see REVIEW.md>
disallowedTools: <explicit denials if inheriting>
# model: omit to inherit, or use plain: model: sonnet
permissionMode: <default|acceptEdits|dontAsk|plan>
---

<System prompt: Who the subagent is, what it does, how it works>

For global subagents: After writing, run:

• chezmoi diff to preview
• chezmoi apply ~/.claude/agents/<name>.md to deploy
• chezmoi status to verify

For local subagents: Restart Claude Code or run /agents to load immediately.

4. Principles

Frontmatter:

• description: Include "proactively" or "Use immediately after..." for auto-delegation
• tools: Minimal subset—subagents inherit all tools by default, so use disallowedTools to restrict
• model: Match to task complexity (see MODEL-SELECTION.md)
• permissionMode: Use dontAsk for read-only, acceptEdits for trusted modification

System Prompt (body):

• Define role clearly: "You are a..."
• Specify when to activate: "When invoked..."
• List concrete steps or checklist
• Describe output format
• Keep under 50 lines—focused specialists, not generalists

Key Differences from Skills:

• Subagents run in isolated context (separate from main conversation)
• Cannot spawn other subagents (no nesting)
• Use tools/disallowedTools instead of allowed-tools
• Body is the system prompt, not playbook instructions

5. Review (REQUIRED)

Spawn a reviewer agent with this skill's REVIEW.md file to audit:

• tools against red flags (reject broad patterns like all tools when minimal set needed)
• Is disallowedTools used to restrict inherited capabilities?
• Permission mode appropriate for the task?
• System prompt clear and focused?

Quick Reference

Goal	Frontmatter
Auto-delegation	description with "proactively"
Read-only	disallowedTools: Write, Edit or tools: Read, Glob, Grep
Fast/cheap	model: haiku
Capable	model: sonnet or model: opus
Skip prompts	permissionMode: dontAsk (auto-deny) or acceptEdits
Exploration	permissionMode: plan
Inject knowledge	skills: [skill-name, ...]
Validate operations	hooks: { PreToolUse: [...] }

Supplementary Docs

• REVIEW.md - REQUIRED checklist for auditing tools before deployment
• MODEL-SELECTION.md - When to use haiku vs sonnet vs opus
• HOOKS.md - Adding lifecycle hooks to subagents

Examples

/write-subagent                              → extract subagent from current conversation (will ask about scope)
/write-subagent global code-reviewer         → global subagent for code review (via chezmoi)
/write-subagent local db-query               → project-local subagent for database queries
/write-subagent in ~/.claude/agents/ search  → global subagent (explicit path)
/write-subagent in .claude/agents/ lint      → local subagent (explicit path)

Scope Decision Guide

Choose global when...	Choose local when...
Subagent is useful across many projects	Subagent uses project-specific conventions
General-purpose task (review, debug, test)	Requires project-specific tools/config
You want it in your dotfiles	Team members should have it too
Personal workflow preference	Repo-specific domain knowledge

Anti-patterns

• Inheriting all tools when minimal set suffices
• Missing disallowedTools for write operations on read-only agents
• Verbose system prompts (over 50 lines)
• Generic descriptions that don't help Claude decide when to delegate
• Using subagents for tasks that need main conversation context
• Global subagent for project-specific logic