Why use fresh subagent instances for testing?

Fresh instances ensure a clean slate for every test, providing a consistent baseline state and isolating the specific impact of the skill being evaluated.

What are rationalization guardrails?

These are internal logic patterns that prevent the AI from providing post-hoc justifications for errors, ensuring the skill remains robust and follows its intended instructions.

How does the three-phase TDD approach work for skills?

It involves Phase 1 (Red) to establish baseline behavior without the skill, Phase 2 (Green) to measure improvements with the skill loaded, and Phase 3 (Refactor) to test anti-rationalization guardrails.

What is priming bias in Claude Code skills?

Priming bias occurs when previous conversation context influences results, making it difficult to tell if a skill is working effectively or if Claude is simply following recent history.

Subagent Skill Testing

Name: Subagent Skill Testing
Author: athola

byathola

•

123

•

Security & Testing

Validates Claude Code skills using a TDD-style methodology and fresh subagent instances to eliminate priming bias.

This skill provides a rigorous framework for testing and validating Claude Code skills by leveraging fresh subagent instances to ensure objective evaluation. It helps developers avoid the 'priming problem' where prior conversation history skews results, allowing for precise measurement of a skill's impact on Claude's behavior. By implementing a three-phase TDD approach—Baseline, With-Skill, and Rationalization—users can systematically confirm that their custom skills are effective, reproducible, and resistant to post-hoc justification.

Key Features

01Comparative analysis framework for skill-related metrics

02Three-phase TDD methodology (Baseline, With-Skill, Rationalization)

03Fresh instance isolation to prevent conversation priming bias

04Anti-rationalization guardrail validation and testing

05123 GitHub stars

06Reproducible testing patterns across diverse scenarios

Use Cases

01Measuring the behavioral impact of skill updates during development

02Validating the effectiveness of a newly authored Claude Code skill

03Testing skill resilience against rationalization and prompt leakage

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add athola/claude-night-market subagent-testing

For use in Claude.ai and ChatGPT

Download Skill