How do I create a custom tool with authentication in ADK?

[thalha-1]

I'm trying to create a custom ADK tool that authenticates to an external API. I have a basic function but I'm not sure how to handle API keys properly within the tool definition.

def my_api_tool(query: str) -> dict:
    # How should I handle auth here?
    response = requests.get("https://api.example.com", params={"q": query})
    return response.json()

What's the recommended pattern for secure credential management in ADK custom tools?