How refreshing, I haven't seen someone push PARC down the memory hole all week.
The tool/command distinction may be useful for a programmer...but reflecting it in the user interface is hardly modern practice.
Creating a rigid user interface base on what is convenient for trainers and programmers, well that's just bad design + an excuse.
And the fact that you have to explain the tool/command distinction is evidence thereof.
BTW, it's good to know that the stack layers button "serves no useful purpose whatsoever," despite its obvious utility.
You should add that to your signature.