Surely this has been requested before but just in case it hasn't (or if people have forgotten), I want to suggest it again, as I hit this a lot.
When I create an abstractions, I almost always have #n arguments to be passed in to it. Some of the abstractions require 5 or 6 parameter, for example, I have a MIDIClickTrackGenerator that takes 5 arguments to define regular and accented notes, velocities for each of them, and a duration.
So after I type in the name of the object, it would be really nice if Max would prompt (or insert) argument names so I don't have to keep going back to the original abstraction to see what it needs.
Now, I understand the object doesn't get instantiated until you have finished typing in everything but perhaps a special object or "metacomment" in the abstraction itself could be recognized by Max whenever you save it so as to add the info to some central registry.