# mcp-prompt-lab

> Use this tool when you need to evaluate and compare the performance of multiple Large Language Models (LLMs) on specific test cases, or when you want to assess the quality of prompts and track their effectiveness over time. It allows users to define test cases, run prompts, and score outputs with various assertions. The tool provides a comprehensive interface for inputting test cases and prompts, and outputs scored results and quality metrics.

Canonical page: https://skillsregistry.net/skills/nikolasbarwicki-mcp-prompt-lab  
JSON: https://api.skillsregistry.net/v1/skills/nikolasbarwicki-mcp-prompt-lab

## Description

A local MCP server for prompt evaluation, enabling users to define test cases, run prompts against multiple LLM providers, score outputs with deterministic and LLM-graded assertions, and track quality over time, all within an AI coding environment.

## Trust

- **Trust score (0–1):** 0.69
- **Verification tier:** scanned
- **Last scanned:** 2026-09-01

## Facts

- **Version:** 1.0.0
- **Skill type:** atomic
- **Execution layer:** mcp-remote
- **Runtime environment:** api
- **Category:** ai-ml
- **Updated:** 2026-09-01

## Source

- **Source listing:** [Glama](https://glama.ai/mcp/servers/xmdy5k03cz)
- **Repository:** <https://github.com/nikolasbarwicki/mcp-prompt-lab>

## Use it

Resolve this record through the SkillsRegistry MCP server (no auth, read-only):

```
claude mcp add --transport http --scope user skillsregistry https://api.skillsregistry.net/mcp
```

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_skill",
    "arguments": {
      "slug": "nikolasbarwicki-mcp-prompt-lab"
    }
  }
}
```

REST: `GET https://api.skillsregistry.net/v1/skills/nikolasbarwicki-mcp-prompt-lab` · pull for local use: `GET https://api.skillsregistry.net/v1/skills/nikolasbarwicki-mcp-prompt-lab/pull`

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SkillsRegistry indexes agent skills from public registries and GitHub. Skills we have analysed are scanned with Circle-IR and scored on six dimensions; each listing states its scan coverage. More: https://skillsregistry.net/llms.txt