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WORK IN PROGRESS - USE WITH CAUTION - Windows

@hanweg

About WORK IN PROGRESS - USE WITH CAUTION - Windows

MCP server that creates its own tools as needed

Basic information

Category

Other

Transports

stdio

Publisher

hanweg

Config

Add this server to your MCP-compatible client using the configuration below.

{
  "mcpServers": {
    "mcp-tool-builder": {
      "command": "uv",
      "args": [
        "venv"
      ]
    }
  }
}

Tools

No tools detected

We auto-extract tools from the README. The maintainer can list them under a ## Tools heading to populate this section.

Overview

What is MCP Tool Builder?

MCP Tool Builder is an MCP server that enables LLMs to dynamically create new tools through MCP clients such as Claude Desktop. It allows users to define new tools using natural language, which are then saved as Python scriptlets and made available after a client restart.

How to use MCP Tool Builder?

Install by cloning the repository, creating a Python virtual environment, activating it, and running uv pip install -e .. Add the server to claude_desktop_config.json using the uv command pointing to the installation directory. Invoke the create_tool command in Claude Desktop to define a new tool; the client must be restarted before the new tool can be used.

Key features of MCP Tool Builder

  • Create tools by describing them in natural language.
  • New tools saved as Python scriptlets.
  • Tool definitions stored in a tools.json file.
  • Includes example tools: get_bitcoin_price and get_weather_forecast.

Use cases of MCP Tool Builder

  • Dynamically extend Claude Desktop with custom tools on demand.
  • Add a Bitcoin price fetcher without manual coding.
  • Create a weather forecast tool for any US ZIP code.
  • Rapidly prototype and test new tool ideas through conversation.

FAQ from MCP Tool Builder

How do I create a new tool?

Use the create_tool command in Claude Desktop (or suggest it strongly) to generate a tool dynamically from a natural language description.

What happens after I create a tool?

The tool is saved as a Python scriptlet in the tools subdirectory and its definition is recorded in tools.json. You must restart Claude Desktop to see and use the new tool.

What example tools are included?

Two tools are provided: get_bitcoin_price (fetches the current Bitcoin price from CoinGecko) and get_weather_forecast (gets a weather forecast for a US ZIP code using geopy).

What are the runtime requirements?

A Python environment with dependencies installed via uv is required. The server is currently labeled as a Windows work-in-progress.

Where are new tools stored?

Tools are stored as .py files in the mcp-tool-builder\tools folder, and their metadata is saved in mcp-tool-builder\tools\tools.json.

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