Isn't that the point of an API though? To be a black box? The example you provide is fairly simple: you hit these endpoints and get this kind of data.
If you need to add data to one endpoint and see how that travels to other endpoints, that makes sense as to why you want documentation. In that case, a product / API tutorial or recipe (like the author suggests) might be useful.
If you need to add data to one endpoint and see how that travels to other endpoints, that makes sense as to why you want documentation. In that case, a product / API tutorial or recipe (like the author suggests) might be useful.