{
  "$schema": "https://json.schemastore.org/mcp.json",
  "name": "the-most-useful-site-in-the-world",
  "displayName": "The Most Useful Site in the World — 1424 Browser Tools",
  "description": "Catalogue of 1424 free, client-side tools (calculators, converters, generators, simulators) across 35 categories. Every tool is a visual, privacy-preserving browser tool; the machine specs under api/tools/<slug>.json describe inputs, outputs, formula and sources so agents can link to or reimplement a tool without scraping HTML.",
  "homepage": "https://www.themostusefulsiteintheworld.com/",
  "version": "2026-09-19",
  "icons": [{ "src": "https://www.themostusefulsiteintheworld.com/favicon.ico", "sizes": ["48x48"] }],
  "tools": [
    {
      "name": "list_tools",
      "description": "List all 1424 tools with category, slug, and description. Filter by category or free-text query.",
      "endpoint": "https://www.themostusefulsiteintheworld.com/api/tools.json",
      "method": "GET"
    },
    {
      "name": "describe_tool",
      "description": "Full machine spec for one tool (inputs, outputs, formula, sources, embed URL).",
      "endpoint": "https://www.themostusefulsiteintheworld.com/api/tools/{slug}.json",
      "method": "GET",
      "parameters": { "type": "object", "required": ["slug"], "properties": { "slug": { "type": "string", "description": "Tool slug, e.g. bmi, mortgage, compoundinterest" } } }
    },
    {
      "name": "open_tool",
      "description": "Open the interactive tool in the user's browser.",
      "endpoint": "https://www.themostusefulsiteintheworld.com/tool.html?card={slug}",
      "method": "GET",
      "parameters": { "type": "object", "required": ["slug"], "properties": { "slug": { "type": "string" } } }
    }
  ],
  "categories": 27,
  "totalTools": 1194,
  "manifests": {
    "cards": "https://www.themostusefulsiteintheworld.com/cards/cards.json",
    "cardsLite": "https://www.themostusefulsiteintheworld.com/cards/cards-lite.json",
    "toolsIndex": "https://www.themostusefulsiteintheworld.com/tools-index.json",
    "perToolSpecs": "https://www.themostusefulsiteintheworld.com/api/tools.json",
    "llmsTxt": "https://www.themostusefulsiteintheworld.com/llms.txt",
    "llmsFullTxt": "https://www.themostusefulsiteintheworld.com/llms-full.txt",
    "sitemap": "https://www.themostusefulsiteintheworld.com/sitemap.xml"
  },
  "notes": "All outputs are static JSON/HTML. No auth, no POST, no server-side computation. YMYL tools (Health & Fitness, Finance & Money) include disclaimers in their deep pages under /tools/<slug>.html. Instrumentation is privacy-preserving and capped; see docs/INSTRUMENTATION.md."
}