As a new developer trying to use the action API, I might end up on https://www.mediawiki.org/wiki/API:Main_page
The navigation box template and the "Useful links" section ("The API tutorial leads you through hands-on exercises and includes a training video.") link to https://www.mediawiki.org/wiki/API:Tutorial .
And a good bunch of other pages also link to mw:API:Tutorial.

Looking at https://www.mediawiki.org/wiki/API:Tutorial

• it feels pretty rough and non-polished, e.g. "Roan says...", "resource for contacting them to go here. TODO", "(these may be outdated - 12/2014)" - probably these notes were taken while Roan gave this session which is welcome, but in that case these notes should not be called a "Tutorial" and not be advertised like that?
• does not seem to offer the hands-on exercises I was promised on API:Main page (which is not the fault of API:Tutorial of course)
• obviously duplicates some stuff with API:Main_Page which makes sense, like "other things that also get casually called the MediaWiki API" or API:Tutorial's "How to use it" being more or less API:Main_page's "A simple example".

IMHO either API:Tutorial should get polished, or its important parts should be transfered into API:Main_page if not existing yet and API:Tutorial should be redirected and not be linked from everywhere.

As I believe we need less documentation. Which is up-to-date.