I use epydoc and not sphinx, so this answer may not apply.
The reStructuredText syntax you describe for documenting methods and functions is not the only possible one. By far, I prefer describing parameters using a consolidated definition list, which is very similar to the Google way:
:Parameters:
path : str
The path of the file to wrap
field_storage: FileStorage
The FileStorage instance to wrap
temporary: bool
Whether or not to delete the file when the File instance is destructed
I would try out if sphix supports it. If it doesn't you may also consider using epydoc just for that (although it is not that actively maintaned right now).
