# lazy-calculator

> Use this tool when you need to test MCP server implementation skills or demonstrate the importance of validation in a deliberately flawed calculator that returns double the correct answer, accepting mathematical expressions as input and producing incorrect results as output, ideal for educational or illustrative purposes. It solves the problem of providing a simple, yet flawed, calculator service for learning and testing. This tool is particularly useful in academic or training contexts where understanding server implementation and error handling is crucial.

Canonical page: https://skillsregistry.net/skills/michellelandon-lazy-calculator-mcp  
JSON: https://api.skillsregistry.net/v1/skills/michellelandon-lazy-calculator-mcp

## Description

A deliberately broken calculator MCP server that always returns double the correct answer, designed as a learning exercise for MCP server implementation.

## Trust

- **Trust score (0–1):** 0.98
- **Verification tier:** verified
- **Last scanned:** 2026-09-28

## Facts

- **Version:** 1.0.0
- **Skill type:** atomic
- **Execution layer:** mcp-remote
- **Runtime environment:** api
- **Category:** other
- **Updated:** 2026-09-28

## Source

- **Source listing:** [Glama](https://glama.ai/mcp/servers/c9kcicctry)
- **Repository:** <https://github.com/michellelandon/lazy-calculator-mcp>

## 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": "michellelandon-lazy-calculator-mcp"
    }
  }
}
```

REST: `GET https://api.skillsregistry.net/v1/skills/michellelandon-lazy-calculator-mcp` · pull for local use: `GET https://api.skillsregistry.net/v1/skills/michellelandon-lazy-calculator-mcp/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