Unless I'm missing something, you can mouse over a unit to see what spells/debuffs/buffs/etc are affecting a unit, but there's no way to actually see what those abilities *do*

Viewing the unit details shows that units abilities, stats, spells, and equipment, but it does not appear to show any abilities affecting it.

Consequently, I have no idea what many enemy buffs are doing, which makes it difficult to plan or counter - I ran into an enemy hero packing something like 8 buff spells, and it was dodging and mana shielding all of my attacks while causing fear, but I had no idea what those abilities were doing, or how to get around them because there were no tooltips or other information on them.