MCP Server Not Showing in Claude Desktop? Here’s What I Did

Member-only story

In the previous article (thumbnail below), I built a “Math MCP Server” using FastMCP and tested it via MCP Inspector — optional read.’

This article covers connecting that local MCP server to Claude Desktop on Windows.

Register MCP Server with Claude-Desktop

This is the main.py file of a local “Math MCP server” and we have added 2 basic tools (square and square root — shown below)

@mcp.tool()
def square(number: float) -> float:
    """
    Calculate the square of a number.
    Args:
        number (float): Input number
    Returns:
        float: Square of the input number
    """
    return number * number
@mcp.tool()
def square_root(number: float) -> float:
    """
    Calculate the square root of a number.
    Args:
        number (float): Input number
    Returns:
        float: Square root of the input number
    Raises:
        ValueError: If the number is negative
    """
    if number < 0:
        raise ValueError("Square root of negative numbers is not allowed.")
    return sqrt(number)