eval_builder

Generate eval.md evaluation criteria with test cases and run instructions.

7|Updated May 6, 2026
One-click install
npx skills add https://github.com/tya5/reyn --skill eval-builder
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: eval_builder
Source: https://github.com/tya5/reyn/tree/main/src/reyn/stdlib/skills/eval_builder
Command: npx skills add https://github.com/tya5/reyn --skill eval-builder

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

It automates the creation of detailed evaluation specifications (eval.md) that assess a skill’s correctness and quality.

Core Features & Use Cases

  • Criteria Generation: Designs specific, evidence-bound quality criteria for each phase of a skill’s workflow.
  • Test Case Design: Creates representative test cases that probe typical, edge, and failure scenarios.
  • Use Case: Facilitates objective assessment of skill outputs by generating a comprehensive eval.md file aligned with phases and criteria, enabling consistent performance measurement.

Quick Start

Invoke the eval_builder skill to generate an eval specification for a given skill name.

Frequently Asked Questions about eval_builder

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

FAQPage Schema
How do I generate evaluation criteria for testing a skill's performance?

To generate evaluation criteria for testing skill performance, you can use an automated eval builder that creates a detailed eval.md document containing specific test cases, quality standards, and run instructions for objective assessment.

What is an eval.md specification and when do I need one for assessment?

An eval.md specification is a document containing evidence-bound quality criteria and test cases for assessing skill correctness. You need one when you want to objectively measure and verify skill behavior across typical and edge scenarios.

How do I create test cases that cover edge scenarios for skill evaluation?

You can create test cases for edge scenarios by designing an evaluation specification that probes typical, edge, and failure conditions, producing observable, criterion-based verification of skill behavior and referencing existing artifacts when available.

Can I evaluate skill outputs without writing manual quality standards?

Yes, you can evaluate skill outputs without manual standards by automating criteria generation. The tool designs specific, evidence-bound quality criteria for each workflow phase, enabling consistent performance measurement without manual specification writing.

What is the best way to structure run instructions for skill assessment?

The best way to structure run instructions for skill assessment is to align them with workflow phases and quality criteria within a comprehensive eval.md document, ensuring consistent performance measurement and observable verification of skill behavior.