It would be nice if some sort of symbol appeared next to deck names signifying that they have some sort of problem that needs to be addressed. I'm referring specifically to the list of decks on the left-hand side of the page, not in the deckbuilding screen. Maybe like a red/yellow exclamation point. Just something small to let us know if a deck doesn't have enough cards, has illegal cards (if you have the ability to implement the banlists), or contains cards missing from your collection.