When creating a CMS Collection field, I love being able to add the help text as it helps the client understand what the field is for and how they should use it. What would be amazing is carrying this idea over for the overall CMS Collection, so that a client can in the same manner understand what the collection does and how they should use it.
For simple sites this may not be necessary, but for instance I have one client site with 14 different CMS Collections, and even though I ran through each one with them, they will periodically come back and ask how things work as they keep forgetting. Having the ability to add a simple description at the top of each CMS Collection that displays in the Editor would be awesome! :)