Forgive me if I'm a total n00b, but I don't think part of becoming good at a game should involve having to figure out a lot of unwritten rules. I have never seen, for instance, a poker game where someone got a surprise when they lost a hand with 4 of a kind aces, to someone with 4 of a kind 3's, because in that game, 3's are high.
In fact, it would be looked down upon, I imagine, because most people don't like hidden rules.
Not every single detail has to be put into a card, no. I would like to see the stats of an animated weapon given on the card, but in the example of the titan, the card itself does say shield effects are ignored, in addition to momentum, not only that it has an ability, but a little of what that ability means, which is probably more than actually needed.
With the example of adrenaline, well...I never used it, but I just learned something about it. I thought it gave lower HP creatures more attack, since "smaller" refers to HP, or so I thought. It would be nice if "smaller" were standard though the game (otyughs eat smaller creatures, but this feeds off HP, so how can a 1/80 creature get 4 attacks from adrenaline, because its a small creature, while a 80/1 creature is small enough to be eaten, but its too large to get a boost from adrenaline.
Also, for it being about one creature...that's for now. If there are never going to be new cards, ok, we can skip it, probably, but there is no reason to believe that there will be only one ability that can be used more than once per turn, for as long as this game exists.
This is turning out to be larger than the topic of this specific thread, so I won't go on here, but I will just say again, the text of the shard does not say that it affects abilities in any way, other than making it free, which seems to be a problem with the text, in this situation.