llm-eval-harness

Builds an LLM evaluation harness using golden datasets and code-based scorers.

9|3|Updated Jun 13, 2026
One-click install
npx skills add https://github.com/Sir-chawakorn/sanook-cli --skill llm-eval-harness
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: llm-eval-harness
Source: https://github.com/Sir-chawakorn/sanook-cli/tree/main/skills/llm-eval-harness
Command: npx skills add https://github.com/Sir-chawakorn/sanook-cli --skill llm-eval-harness

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This skill solves the problem of non-deterministic output quality in AI agents and LLM applications by replacing subjective vibes-based testing with a structured, reproducible regression testing framework.

Core Features & Use Cases

  • Multi-Layered Scoring: Combines deterministic code-based scorers (regex, JSON schema) with LLM-as-judge evaluation for semantic quality.
  • Regression Gates: Prevents performance degradation by comparing new model/prompt outputs against a committed baseline dataset.
  • Use Case: When updating a RAG system's retrieval configuration, use this harness to ensure that the new configuration maintains or improves faithfulness and correctness scores across a golden dataset of production-derived test cases.

Quick Start

Use the llm-eval-harness skill to initialize a new evaluation suite by defining your golden dataset and configuring the code-based scorers for your specific agent output.

Frequently Asked Questions about llm-eval-harness

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

FAQPage Schema
How do I build a regression gate for LLM outputs?▼

To build a regression gate for LLM outputs, define a golden dataset and rubric to compare candidate outputs against established baselines, preventing performance degradation when updating prompts or models.

What is the best way to test RAG configuration updates?▼

Testing RAG configuration updates is best done by running an evaluation harness across a golden dataset of production-derived test cases to ensure new retrievals maintain or improve faithfulness and correctness scores.

Do I need a specific data format to start LLM regression testing?▼

Yes, you need a structured JSONL or CSV dataset to initialize the evaluation suite, providing the baseline data required to compare new agent outputs against committed baselines.

Can I use code-based scorers instead of LLM-as-judge for evaluation?▼

Yes, you can configure deterministic code-based scorers like regex and JSON schema validation independently or combine them with LLM-as-judge mechanisms for multi-layered evaluation of agent outputs.