What Drives Me Crazy When Integrating With a New API?

I was directed to an API question today, that needs to be asked constantly in the space:

My response was:

This is such a relevant topic I wanted to continue the conversation by listing the top 10 things that drive me crazy when integrating with a new API:

All nine of these items go into establishing trust between API provider and consumer. There are some APIs I just trust and others I don’t. Delivery in these nine areas, all feed into whether I trust an API for my business or not

I depend on 21 separate APIs for my business. I’m working to add more to this stack, and as a developer I can identify if an API has value within seconds, and hopefully have it integrated with in minutes or at the most a couple of hours.  

As an API provider, make sure and find out what drives your developers crazy while integrating, and see what you can do to reduce friction in these nine areas.