documentation of tools.deprecation is missing. Instead of it the following is shown:

tools.deprecated(*outer_args, **outer_kwargs)[source]
Outer wrapper.

The outer wrapper may be the replacement function if the decorated decorator was called without arguments, or the replacement decorator if the decorated decorator was called without arguments.

PARAMETERS:
outer_args – args
outer_kwargs – kwargs

But this is the documentation of the outer wrapper of the add_fullname decorator.