What is this hook supposed to do?
If your module doesn't need to implement any other hooks, then yep, hook_views_api() is all you need in your .module file. 

As long as you provide the right path in hook_views_api(), Views will know where to look and will dynamically include the files when they're needed.

Usually you need to put files[] = mymodule.FILENAME.inc in your module's .info file for the dynamic code registry to pick it up, but from the looks of it that isn't the case for Views.

If you're looking for some code examples for this, take a look at the Administration Views module; it's .module file contains only hook_views_api() as well (and it works), so you can be confident you're doing the right thing.