the reason they don't have tooltips for it (which depends on how long a process that would take to even add that in there), would be the same as unique/untradeable ingame. They don't put those on there because you can sell the cards for MGP to the npc in the TT section. I believe that may be the reason why it's not added. If it was, it'd be the unique/untradeable version where you can't sell it and just need to drop it. But some of those cards make for good MGP once sold. Some going as good as 5k i think? Or 10k for some of the cards you get from those dungeons too.