What are the key benefits of defining MCP tools with decorators?

The decorator approach gives you several practical benefits. There is no manual JSON schema writing required, because the SDK generates the schema from your Python type hints. Type hints also provide automatic validation, so invalid arguments are rejected before your code even runs. Clear parameter descriptions, supplied through Pydantic Field, help Claude understand correct tool usage. Error handling integrates naturally with regular Python exceptions, so you raise an error and the protocol layer reports it cleanly to the client. And tool registration happens automatically through the decorators themselves, so adding a new tool is just adding a new decorated function.