Hi there!
In some tutorial videos I’ve seen the big descriptions for element
Please look at example below
in Tutorial video:
in my Editor:
How can I config editor for displaying descriptions like on the first image?
No special configuration is needed, you hold (Ctrl + Alt) for more as advertised:
It simply does not work everywhere. I’ve always felt that which tooltip is displayed where is a bit random, but it might be just me. What is showed in pic1 can be seen when hovering over Actor variable, I think it also shows when one creates a new Actor in the Content Browser.
Doesn’t work

what is your version of UE?
because it’s dont work everywhere
4.25 - same as yours.
so might be the reason why I dont see such description of the Actor in the Class Viewer