Subagent Driven Development

Subagent Driven Development

Core Concept

FRESH AGENT = FRESH CONTEXT
Use subagents for focused work without baggage

When to Use Subagents

Situation	Why Subagent Helps
Complex subtask	Focused context, clear scope
Going in circles	Fresh perspective breaks loops
Parallel work	Multiple things at once
Context pollution	Main agent too cluttered
Specialized task	Pass only relevant info
Research/exploration	Keep main context clean

How to Launch Subagent

The Handoff:

1. DEFINE clear scope - what exactly to do
2. PROVIDE needed context - files, constraints, requirements
3. SPECIFY deliverable - what to return
4. SET success criteria - how to know it's done

Template:

Task: [Specific action to take]

Context:
- Working in [repo/directory]
- Relevant files: [list]
- Constraints: [any limits]

Deliverable:
- [Exact output expected]

Success when:
- [Criteria 1]
- [Criteria 2]

Anti-Patterns

❌ Vague handoffs

Bad: "Look into this bug"
Good: "Find root cause of TypeError in user.ts:45"

❌ Context dumping

Bad: Passing entire conversation history
Good: Passing only relevant files and specific question

❌ No success criteria

Bad: "Make it better"
Good: "Refactor to reduce duplication, all tests must pass"

❌ Too broad scope

Bad: "Implement the whole feature"
Good: "Implement the validation logic for email field"

Good Subagent Tasks

✅ Research:

• "Find how X is implemented in this codebase"
• "Search for similar patterns in the repo"
• "Understand the data flow from A to B"

✅ Focused fixes:

• "Fix the specific test failure in X"
• "Resolve the lint error in file Y"
• "Update function Z to handle edge case"

✅ Generation:

• "Generate tests for this function"
• "Create documentation for this module"
• "Write migration for schema change"

✅ Analysis:

• "Analyze dependencies of this module"
• "Identify all usages of this API"
• "Review this PR for issues"

Receiving Subagent Results

When subagent returns:

1. READ the full response
2. VERIFY against success criteria
3. INTEGRATE results into main context
4. CONTINUE from where you left off

Integration with Checkers

Before launching subagent:

• scope-boundary-checker → Is scope clear and bounded?
• assumption-checker → Are handoff assumptions valid?

After receiving results:

• fact-checker → Verify subagent claims
• pre-action-verifier → Before using results

Context Management

Main agent responsibilities:

• High-level plan
• User communication
• Final integration
• Overall progress

Subagent responsibilities:

• Focused execution
• Detailed work
• Return clean results
• No side conversations