Create specialized Claude Code sub-agents with custom system prompts and tool configurations. Use when users ask to create a new sub-agent, custom agent, specialized assistant, or want to configure task-specific AI workflows for Claude Code.
Content & Writing
258 Stars
103 Forks
Updated Dec 17, 2025, 03:28 AM
Why Use This
This skill provides specialized capabilities for greatSumini's codebase.
Use Cases
Developing new features in the greatSumini repository
Refactoring existing code to follow greatSumini standards
Understanding and working with greatSumini's codebase structure
---
name: subagent-creator
description: Create specialized Claude Code sub-agents with custom system prompts and tool configurations. Use when users ask to create a new sub-agent, custom agent, specialized assistant, or want to configure task-specific AI workflows for Claude Code.
---
# 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
```markdown
---
name: subagent-name
description: When to use this subagent (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/bypassPermissions/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 for auto-delegation) |
| `tools` | No | Comma-separated tool list (omit to inherit all) |
| `model` | No | `sonnet`, `opus`, `haiku`, or `inherit` |
| `permissionMode` | No | `default`, `acceptEdits`, `bypassPermissions`, `plan` |
| `skills` | No | Skills to auto-load |
## Creation Workflow
1. **Gather requirements**: Ask about the sub-agent's purpose, when to use it, and required capabilities
2. **Choose scope**: Project (`.claude/agents/`) or user (`~/.claude/agents/`)
3. **Define configuration**: Name, description, tools, model
4. **Write system prompt**: Clear role, responsibilities, and output format
5. **Create file**: Write the `.md` file to the appropriate location
## Writing Effective Sub-agents
### Description Best Practices
The `description` field is critical for automatic delegation:
```yaml
# Good - specific triggers
description: Expert code reviewer. Use PROACTIVELY after writing or modifying code.
# Good - clear use cases
description: Debugging specialist for errors, test failures, and unexpected behavior.
# Bad - too vague
description: Helps with code
```
### System Prompt Guidelines
1. **Define role clearly**: "You are a [specific expert role]"
2. **List actions on invocation**: What to do first
3. **Specify responsibilities**: What the sub-agent handles
4. **Include guidelines**: Constraints and best practices
5. **Define output format**: How to structure responses
### Tool Selection
- **Read-only tasks**: `Read, Grep, Glob, Bash`
- **Code modification**: `Read, Write, Edit, Grep, Glob, Bash`
- **Full access**: Omit `tools` field
See [references/available-tools.md](references/available-tools.md) for complete tool list.
## Example Sub-agents
See [references/examples.md](references/examples.md) for complete examples:
- Code Reviewer
- Debugger
- Data Scientist
- Test Runner
- Documentation Writer
- Security Auditor
## Template
Copy from [assets/subagent-template.md](assets/subagent-template.md) to start a new sub-agent.
## Quick Start Example
Create a code reviewer sub-agent:
```bash
mkdir -p .claude/agents
```
Write to `.claude/agents/code-reviewer.md`:
```markdown
---
name: code-reviewer
description: Reviews code for quality and security. Use proactively after code changes.
tools: Read, Grep, Glob, Bash
model: inherit
---
You are a senior code reviewer.
When invoked:
1. Run git diff to see changes
2. Review modified files
3. Report issues by priority
Focus on:
- Code readability
- Security vulnerabilities
- Error handling
- Best practices
```