eval

Define and run capability evals with code and model graders.

Updated Aug 23, 2026
One-click install
npx skills add https://github.com/fancive/claude-skills --skill eval-fancive
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: eval
Source: https://github.com/fancive/claude-skills/tree/main/skills/eval
Command: npx skills add https://github.com/fancive/claude-skills --skill eval-fancive

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Eval-Driven Development enables teams to define and manage capability/regression evaluations before coding, ensuring measurable quality throughout the lifecycle.

Core Features & Use Cases

  • Define eval definitions for capabilities and regression checks.
  • Run code-based graders and model-based graders to validate changes.
  • Automatically generate and save reports and baselines for comparison.

Quick Start

Start by creating an eval definition with /eval define <name>, then run checks with /eval check <name> and finally generate a report with /eval report <name>.

Frequently Asked Questions about eval

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

FAQPage Schema
Can I apply eval definitions across planning, development, and post-implementation review?

Yes, you can apply eval definitions across planning, development, and post-implementation review. The workflow supports establishing benchmarks early, validating changes during development, and generating final reports to ensure measurable capability and regression checks are met.

What is eval-driven development and when do I need it?

Eval-driven development is the process of defining capability and regression evaluations before writing code. You need it when you want to establish measurable quality benchmarks, ensuring that development progress is validated against baseline metrics rather than subjective standards.

How do I run code-based and model-based graders to validate changes?

To run code-based and model-based graders, you execute a check command against your defined eval name. This validates your changes by running the graders and automatically saving the results and baselines for comparison against future runs.

How do I generate a report with pass@k metrics for my evaluations?

You generate a report with pass@k metrics by executing a report command with your eval name. This produces a comprehensive report summarizing the evaluation results, allowing you to review capability scores and regression status.

Can I apply eval definitions across planning, development, and post-implementation review?

Yes, you can apply eval definitions across planning, development, and post-implementation review. The workflow supports establishing benchmarks early, validating changes during development, and generating final reports to ensure measurable capability and regression checks are met.