MCP Dynamic Tools

Drop Python files, get MCP tools instantly.

A dynamic MCP server that automatically discovers Python files in a directory and exposes them as tools to any MCP-compatible AI client. Created through collaboration between Ben Wilson and Claude (Anthropic).

How it works

# 1. Write a Python file or have the LLM write one def invoke(arguments): """Generate a secure password Parameters: - length: Length of password (default: 12) - include_symbols: Include special characters (default: true) """ import random, string length = int(arguments.get('length', 12)) chars = string.ascii_letters + string.digits if arguments.get('include_symbols', 'true').lower() == 'true': chars += "!@#$%^&*" return ''.join(random.choice(chars) for _ in range(length))

# 2. Save it to your tools directory echo "# Above code" > tools/password_generator.py

# 3. AI can now use it immediately (after restart in Claude Desktop) 🤖 "Generate a 16-character password with symbols" 🔧 Tool: password_generator(length="16", include_symbols="true") 📤 Result: "K9#mP2$vR8@nQ3!x"

Related MCP server: Agent Construct

Quick Start

1. Clone and Setup

git clone https://github.com/your-username/mcp-dynamic-tools cd mcp-dynamic-tools

2. Create Tools Directory

mkdir tools

3. Configure Your MCP Client

Claude Desktop (~/.config/claude_desktop_config.json):

{ "mcpServers": { "mcp-dynamic-tools": { "command": "python3", "args": [ "/path/to/mcp-dynamic-tools/src/mcp_dynamic_tools/server.py", "--tools-dir", "/path/to/tools" ] } } }

4. Create Your First Tool

# tools/hello.py def invoke(arguments): """Say hello to someone Parameters: - name: The person to greet """ name = arguments.get('name', 'World') return f"Hello, {name}! 👋"

5. Restart Your MCP Client

Your hello tool is now available to any AI using your MCP client!

How It Works

File Discovery: Server monitors your tools directory
Code Analysis: Validates Python files have invoke(arguments) function
Schema Extraction: Parses docstrings for parameter definitions
MCP Integration: Exposes tools via standard MCP protocol
Error Handling: Provides detailed feedback for debugging

Writing Tools

Function Signature

Every tool must have this exact signature:

def invoke(arguments): # Your tool logic here return result

Documentation Format

def invoke(arguments): """Brief description of what the tool does Parameters: - param_name: Description of the parameter - another_param: Description with (default: value) """

Example Tools

Text Processor:

def invoke(arguments): """Transform text in various ways Parameters: - text: The text to transform - operation: Type of transformation (uppercase, lowercase, reverse) """ text = arguments.get('text', '') operation = arguments.get('operation', 'uppercase') if operation == 'uppercase': return text.upper() elif operation == 'lowercase': return text.lower() elif operation == 'reverse': return text[::-1] else: return f"Unknown operation: {operation}"

API Caller:

def invoke(arguments): """Fetch data from a REST API Parameters: - url: The API endpoint to call - method: HTTP method (default: GET) """ import urllib.request import json url = arguments.get('url') method = arguments.get('method', 'GET') if not url: return "Error: URL is required" try: with urllib.request.urlopen(url) as response: return json.loads(response.read()) except Exception as e: return f"Error: {str(e)}"

Robust Error Handling

The server provides detailed error messages to help you debug:

Syntax Errors: Shows line numbers and specific issues
Import Errors: Reports missing dependencies
Function Signature: Validates invoke(arguments) signature
Runtime Errors: Captures and reports execution problems

Known Limitations

Claude Desktop 0.9.2

Claude Desktop currently doesn't support dynamic tool discovery (see discussion). This means:

✅ Tools work perfectly once discovered
❌ Restart required when adding new tools
🔄 Future support planned - our server is ready with listChanged: true

Workaround: Restart Claude Desktop after adding new tools.

Tool Naming in Claude Desktop

Tools appear with server prefix: local__mcp-dynamic-tools__your_tool_name

Contributing

This project was created through human-AI collaboration. We welcome contributions!

Fork the repository
Create your feature branch
Add tests for new functionality
Submit a pull request

License

MIT License - see LICENSE file for details.

Acknowledgments

Ben Vierck - Architecture and development
Claude (Anthropic) - Co-development and testing
MCP Community - Protocol development and feedback

MCP Dynamic Tools

MCP Dynamic Tools

How it works

Quick Start

1. Clone and Setup

2. Create Tools Directory

3. Configure Your MCP Client

4. Create Your First Tool

5. Restart Your MCP Client

How It Works

Writing Tools

Function Signature

Documentation Format

Example Tools

Robust Error Handling

Known Limitations

Claude Desktop 0.9.2

Tool Naming in Claude Desktop

Contributing

License

Acknowledgments

Resources

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