Show a tooltip "glued to surface" when the move tool can't be locked to non-plain axis


I had a problem (and solved it) as described here:

My object was glued to a surface, which i was not aware of.

So, pressing the down key would, since SU2016, normally lock moving to the plain, but (because the object was already locked i think), a tooltip tells me “Constraint not appropriate at this time” .
Couldn’t there be a similar tooltip saying “Can’t lock onto Axis” or Constraint already set to plain (Glued to surface) … or whatever would make universally sense?


That would be a tidy solution to a problem that arises surprisingly often, especially when people import components from the EW without knowing they have glue-to behavior set.