promptfoo-evaluation

Configure and run Promptfoo evaluations with rubric grading and custom assertions.

Updated Aug 23, 2026
One-click install
npx skills add https://github.com/aleister1102/skills --skill promptfoo-evaluation-aleister1102
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: promptfoo-evaluation
Source: https://github.com/aleister1102/skills/tree/main/promptfoo-evaluation
Command: npx skills add https://github.com/aleister1102/skills --skill promptfoo-evaluation-aleister1102

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Prompt engineering and model benchmarking can be inconsistent and hard to reproduce across teams. This skill provides a structured approach to configure, run, and compare LLM evaluations using Promptfoo, enabling reproducible results.

Core Features & Use Cases

  • Structured evaluation pipelines: configure prompts, tests, and providers in a single project.
  • Automated grading with Python assertions and LLM rubrics for objective comparisons.
  • Model-to-model and provider comparisons across multiple scenarios for QA, research, or product validation.

Quick Start

Initialize a Promptfoo project, load prompts and tests, and run the evaluation to produce results.

Frequently Asked Questions about promptfoo-evaluation

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

FAQPage Schema
How do I set up reproducible LLM evaluation and prompt comparison across models?

Reproducible LLM evaluation requires structuring prompts, tests, and providers into a single configuration. You can standardize this process by applying rubric-based grading and custom assertions to generate consistent model-to-model comparison results.

Can I use Python assertions for automated grading in LLM evaluations?

Yes, Python assertions can be used for automated grading in LLM evaluations. This allows you to apply deterministic checks to model outputs, ensuring objective comparisons across multiple scenarios for QA or product validation.

What is rubric-based grading for benchmarking prompts and how does it work?

Rubric-based grading evaluates LLM outputs against predefined structured criteria. It standardizes the comparison of prompts across different models by scoring responses based on specific test cases and rules, yielding reproducible benchmark results.

How do I configure test cases and providers for model-to-model comparison?

You configure test cases and providers by initializing a structured evaluation project. This involves loading your prompts and tests alongside your model providers to run comprehensive comparisons across various scenarios.

Does LLM evaluation with custom assertions require external scripts?

Custom assertions in LLM evaluation can utilize optional scripts or references to drive deterministic checks. The core requirement is a configuration file defining prompts and tests, while scripts enhance the evaluation logic.

When should I use structured prompt evaluation pipelines instead of manual testing?

Structured prompt evaluation pipelines are necessary when consistency and reproducibility across teams are critical. They replace manual testing by automating rubric-based grading and provider comparisons for robust QA, research, or product validation.