eval-driven-development

Define expected outcomes and run pass@k evals to validate agent behavior changes.

Updated Apr 11, 2026
One-click install
npx skills add https://github.com/bennybennison/agent-toolkit --skill eval-driven-development
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: eval-driven-development
Source: https://github.com/bennybennison/agent-toolkit/tree/main/skills/eval-driven-development
Command: npx skills add https://github.com/bennybennison/agent-toolkit --skill eval-driven-development

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Many teams modify agent rules, skills, or prompts without a reliable way to confirm that changes produce the intended behavior and do not introduce regressions.

Core Features & Use Cases

  • Eval Definition: Write an expected behavior test before making a change.
  • Baseline & Regression Checks: Run the eval against the current version to establish a pass/fail baseline, then re‑run after modifications.
  • Capability Validation: Confirm new capabilities pass a configurable pass@k threshold.
  • Use Cases: Adding a new rule, updating a prompt, or extracting a pattern via continuous learning where confidence in behavior is required.

Quick Start

Prompt the skill to create an eval for a new rule, run the baseline, apply the change, and verify the eval now passes.

Frequently Asked Questions about eval-driven-development

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I validate agent behavior changes before deploying prompt modifications?

You can validate agent behavior by defining an eval with expected outcomes and pass@k criteria before implementation, establishing a baseline, then re-running it after updates to confirm capability and regression performance.

What is eval-driven development for AI agents?

Eval-driven development is a testing approach where you define expected behavior outcomes and pass@k criteria before modifying agent rules, skills, or prompts to assess capability and prevent regressions.

How do I test for regressions when updating agent rules and skills?

You test for regressions by running an eval against the current agent version to establish a pass/fail baseline, applying your rule or skill updates, and re-running the eval to verify the expected outcomes still pass.

Can I use this eval approach for continuous learning pattern extraction?

Yes, you can apply this eval approach to continuous learning pattern extraction by defining expected behavior outcomes and pass@k criteria to ensure confidence in behavior consistency when new patterns are extracted.

What do I need to define before running an agent capability validation?

Before running agent capability validation, you need to define clear input scenarios, expected results, and pass@k criteria to assess whether the agent updates meet the required behavior consistency threshold.

What is the best way to ensure prompt modifications do not break existing agent capabilities?

The best way to ensure prompt modifications do not break existing capabilities is to establish an eval baseline before changes and verify the updated prompt still passes the configured pass@k threshold for expected outcomes.