ricfly747.
Practically you have to double check with ATC as soon as you get the clearance.
There is no right answer, its very country dependant what they expect you to do. Sometimes keeping the 5k will put you stupidly over the glide if you don't descend to the platform height.
"confirm cleared to descend to XXXXft for glide intercept" would the question I would ask.
The reply's so far are what the posters would expect in their own country. As you well know the differences between country's can be quite marked.
The only thing you can do is ask.