What is a tool function in the context of LLMs like Claude?	A Python function that is executed automatically when the LLM decides it needs to retrieve extra information to help the user.
What is the first best practice when creating a tool function?	Use well-named and descriptive arguments for the function.
What is the second best practice for tool functions?	Validate inputs and raise an error immediately if the input is incorrect.
Why is it important that error messages raised by a tool function are meaningful?	So that the LLM can see the error and attempt to correct the tool call in a subsequent attempt.
What is the purpose of the `date format` argument in the `get current date time` function?	To specify how the current date and time should be formatted and returned to the user.
How is the current date and time formatted within the `get current date time` function?	By using `datetime.now().strftime(date_format)`.
What specific validation was added to the `get current date time` function?	Checking if the `date format` argument is an empty string and raising an error if it is.