The title says it.
I think having the full description of a spell will be extremely beneficial to the game. Sometimes it's really hard to understand how much a spell will last, what is going to happen if the enemy passes the saving throw etc. etc.
I understand the choice of displaying simplified versions of spells descriptions was made to help newcomers to the system, but I think is detrimental.
Besides, now that there is the possibility to pinpoint tooltips it will be easier than ever to understand in full what a spell does, without the need to simplify its description.
Peace