Seams to be a good idea
I think this is indeed something that should be added to command line apps & desktop systems (kde too of course).
moreover: wouldn't it be possible (or is there already something like that) to create a kind of (desktop independent) database, where apps may register itself. By registering they tell what kind of app it is, what kind of services it supports, a descriptive string, and so on. Of course then there must be predefined "services" and "application types". For example:
ok, the above names are not very well choosen... but something like that would probably help to search for the "correct" application to perform a specific task for a non-linux guru.
also this system probably wouldn't be aware of very special program-services - but that's no problem. If someone uses an application which does a quite special task, he will know anyway how to use it.