eval-harness

Define and run standardized evals for Claude Code workflows with pass@k metrics.

2|Updated Apr 7, 2026
One-click install
npx skills add https://github.com/Zenobia000/ai-brainstorming --skill eval-harness-zenobia000
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: eval-harness
Source: https://github.com/Zenobia000/ai-brainstorming/tree/main/.claude/custom-rule%26skill/skills/eval-harness
Command: npx skills add https://github.com/Zenobia000/ai-brainstorming --skill eval-harness-zenobia000

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

When building AI-assisted workflows with Claude Code, teams lack a standardized way to define clear success criteria, measure agent reliability, catch regressions from code or prompt changes, and track performance across model versions, leading to unvalidated, unreliable outputs that break unexpectedly.

Core Features & Use Cases

  • Standardized Eval Definitions: Create structured capability and regression eval documents with clear pass/fail criteria before starting development work.
  • Flexible Grader System: Use code-based graders for deterministic checks, model-based graders for open-ended output evaluation, or flag items for human review for high-risk changes.
  • Reliability Metrics: Track pass@k (success within k attempts) and pass^k (all k consecutive successes) metrics to measure and improve agent consistency over time.
  • Use Case: A developer adding a new user authentication feature can use this skill to define evals for the new capability, run regression evals to ensure existing login flows still work, and generate a report to confirm the feature meets reliability thresholds before shipping.

Quick Start

Ask Claude to use the eval-harness skill to define capability and regression evals for your new Claude Code feature and generate a baseline performance report.

Frequently Asked Questions about eval-harness

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

FAQPage Schema
How do I set up eval-driven development for Claude Code workflows?

Agent reliability metrics like pass@k (success within k attempts) and pass^k (all k consecutive successes) measure AI workflow consistency over time. Tracking these metrics helps teams benchmark agent performance across model versions and confirm features meet reliability thresholds before shipping.

Can I use model-based graders for open-ended Claude Code outputs?

To define capability evals for a new Claude Code feature, ask Claude to use the eval-harness skill to generate structured eval documents with pass/fail criteria. You then run baseline evals, apply graders, and generate a performance report confirming the feature meets reliability thresholds.

What is the best way to benchmark Claude Code agent performance across model versions?

Benchmarking Claude Code agent performance across model versions involves running standardized eval definitions with consistent graders and tracking pass@k and pass^k reliability metrics. This approach catches regressions from model updates and provides measurable validation before shipping new capabilities.

Does Claude Code eval testing work with slash command workflows?

Yes, Claude Code eval testing integrates with slash command workflows. The eval harness is designed to work within Claude Code's native slash command interface, allowing teams to define, run, and report on evals without leaving their development environment.