Quite often I work on my code and I don't necessarily enter all the documentation at that point. When I am ready to release the code I update the documentation. Now in case where I have a base class or an interface that is derived or implemented in a multiple classes I have to repeat the same documentation over and over.
It would be nice to be able to create documentation on the base class (interface) and then go to the derived class and press + and select "Documentation from the base class" and it would use the same documentation. (Of course only when that is possible -- when there is a base class or interface and the current method is overriding a base class method or implementing an interface method.) This would save a lot of work for me.