---
name: subagent-testing
description: TDD-style testing methodology for skills using fresh subagent instances
  to prevent priming bias and validate skill effectiveness. Use when validating skill
  improvements, testing skill effectiveness, preventing priming bias, measuring skill
  impact on behavior. Do not use when implementing skills (use skill-authoring instead),
  creating hooks (use hook-authoring instead).
category: testing
tags:
- testing
- validation
- TDD
- subagents
- fresh-instances
token_budget: 30
progressive_loading: true
---

# Subagent Testing - TDD for Skills

Test skills with fresh subagent instances to prevent priming bias and validate effectiveness.

## Table of Contents

1. [Overview](#overview)
2. [Why Fresh Instances Matter](#why-fresh-instances-matter)
3. [Testing Methodology](#testing-methodology)
4. [Quick Start](#quick-start)
5. [Detailed Testing Guide](#detailed-testing-guide)
6. [Success Criteria](#success-criteria)

## Overview

**Fresh instances prevent priming:** Each test uses a new Claude conversation to verify
the skill's impact is measured, not conversation history effects.

## Why Fresh Instances Matter

### The Priming Problem
Running tests in the same conversation creates bias:
- Prior context influences responses
- Skill effects get mixed with conversation history
- Can't isolate skill's true impact

### Fresh Instance Benefits
- **Isolation**: Each test starts clean
- **Reproducibility**: Consistent baseline state
- **Measurement**: Clear before/after comparison
- **Validation**: Proves skill effectiveness, not priming

## Testing Methodology

Three-phase TDD-style approach:

### Phase 1: Baseline Testing (RED)
Test without skill to establish baseline behavior.

### Phase 2: With-Skill Testing (GREEN)
Test with skill loaded to measure improvements.

### Phase 3: Rationalization Testing (REFACTOR)
Test skill's anti-rationalization guardrails.

## Quick Start

```bash
# 1. Create baseline tests (without skill)
# Use 5 diverse scenarios
# Document full responses

# 2. Create with-skill tests (fresh instances)
# Load skill explicitly
# Use identical prompts
# Compare to baseline

# 3. Create rationalization tests
# Test anti-rationalization patterns
# Verify guardrails work
```

## Detailed Testing Guide

For complete testing patterns, examples, and templates:
- **[Testing Patterns](modules/testing-patterns.md)** - Full TDD methodology
- **[Test Examples](modules/testing-patterns.md)** - Baseline, with-skill, rationalization tests
- **[Analysis Templates](modules/testing-patterns.md)** - Scoring and comparison frameworks

## Success Criteria

- **Baseline**: Document 5+ diverse baseline scenarios
- **Improvement**: ≥50% improvement in skill-related metrics
- **Consistency**: Results reproducible across fresh instances
- **Rationalization Defense**: Guardrails prevent ≥80% of rationalization attempts

## See Also

- **skill-authoring**: Creating effective skills
- **bulletproof-skill**: Anti-rationalization patterns
- **test-skill**: Automated skill testing command