Add configuration options for method description when registering tools

When registering tools, I would like the ability to set a maximum length for the function description or override the description parsed from __doc__

openai.BadRequestError: Error code: 400 - {'error': {'message': "Invalid 'tools[0].function.description': string too long. Expected a string with maximum length 1024, but got a string with length 1463 instead.", 'type': 'invalid_request_error', 'param': 'tools[0].function.description', 'code': 'string_above_max_length'}}

For example,

def my_func():
    """
    A really long docstring...
    """
    pass

chat.register_tool(my_func, max_doc_length=1024)

# or

chat.register_tool(my_func, doc="A shorter docstring...")

The entry point mentioned is chat.register_tool; start by locating its implementation and the code that derives descriptions from doc. Done means supporting a maximum description length and an explicit replacement description, including the 1024-character case shown in the report.