I'd argue that this should go the other way around. Your developers should be creating the 'docs' - the API design and boilerplate, before programing it.
If they actually sit down and design the API before setting of to write the code you'll end up with:
(a) the documentation you want.
(b) an API that this designed consistently and consciously.
Would you let your front end developers build something without at least a wire frame / functional design?