create_toolLABSCO SUMMARY
A server whose job is to grow.
Instead of finding a server for every small integration, you describe the call you want and it becomes a tool on disk. The cost is a client restart before it can be used, and the code that gets written is yours to read.
What it is
An MCP server that creates other tools. A tool is described in natural language and saved as a Python scriptlet under the server's tools directory, with its definition written into tools.json alongside it. The new tool becomes usable after the client restarts. Two examples ship with it — a Bitcoin price lookup and a US ZIP-code weather forecast.
What you get
- New tools created from a natural-language description
- Each one saved as a Python scriptlet in the server's tools directory
- Its definition written into tools.json next to the script
- get_bitcoin_price, fetching the current Bitcoin price from CoinGecko
- get_weather_forecast, returning weather for US ZIP codes using geopy
Requirements
Python with uv: the repository is cloned, a virtual environment created, and the package installed with uv pip install -e. The README marks the project work in progress and its setup uses Windows paths. Restart the client after creating a tool — a new one is not available until then.
Setup effort
Build from source — get the source, then follow the steps on this page and add the configuration for your client
USE CASES
01
Getting a one-off integration, no server hunt
Describe the API call you want in words; the scriptlet lands in the tools directory and its definition in tools.json.
02
Keeping the tools you invent
Each generated tool is a Python file on disk, so it survives the session and can be read and edited like any other code.
03
Seeing the shape before writing your own
Two working examples ship with it — a CoinGecko price lookup and a ZIP-code weather forecast — to copy the pattern from.
3 tools
Listed in project docs. Your client may show a different list.
get_bitcoin_priceget_weather_forecastBEFORE YOU INSTALL
What to know first
Tools you get
3 tools named in the project's documentation. The list grows: create_tool writes new tools into tools.json, and they appear after you restart your client.
Requires
uv on PATH
Where it runs
The documented client runs the server on your machine.
INSTALLATION
Connect your client
Get the source, then follow the steps on this page and add the configuration for your client. This one is built from source rather than installed with a single command.
Server setup
Setup
TERMINAL
git clone https://github.com/hanweg/mcp-tool-builder
cd mcp-tool-builder
uv venv
.venv\Scripts\activate
uv pip install -e .uv
TERMINAL
uv --directory <YOUR_PATH_TO_MCP_TOOL_BUILDER> run tool-builderMCP Clients
Any MCP client
ANY MCP CLIENT · JSON
{
"mcpServers": {
"tool-builder": {
"command": "uv",
"args": [
"--directory",
"<YOUR_PATH_TO_MCP_TOOL_BUILDER>",
"run",
"tool-builder"
]
}
}
}
