# Prompt-to-Tool Router

> Describe your problem in plain words and get the right tools and order to use them. Takes a natural-language request (English or German) and ranks the usefulweb.site tools and workflows that can solve it, using transparent keyword matching (TF-IDF with synonyms), and proposes a sequence of tool calls.

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://prompttotoolrouter.usefulweb.site/ (interactive tool at https://prompttotoolrouter.usefulweb.site/tool)
- JSON API: POST https://prompttotoolrouter.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://prompttotoolrouter.usefulweb.site/api/v1/tool)
- OpenAPI: https://prompttotoolrouter.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://prompttotoolrouter.usefulweb.site/mcp - tool `prompt_to_tool_router`

## Inputs
- request (textarea, required): What do you want to do?
- maxResults (integer): Max tools

## Method
- The request is lower-cased, split into words, stop words (EN/DE) removed, lightly stemmed and expanded with a published synonym table.
- Each tool is indexed by name (weight 3), keywords (2.5), id (2) and tagline (1.5); score = Σ weight × ln(1 + N/df) over matched terms, +4 per exact keyword phrase.
- If a workflow scores at least 60% of the best tool score, its steps become the plan; otherwise the top tools are planned in score order.