Artificial Intelligence in Turn-Based RPGs

[Steel Beast 6Beets]

What do you guys think about A.I programed to counter certain actions in battle? For example a boss who hates magic and will attack anyone casting spells on it with a silencing skill?

Right how I just have the AI run all options, and choose the one that is most effective (based on damage + states applied - states removed). The problem with this is it might make the AI "too good", and allow it to avoid things it shouldn't know about (It's not fun if you equip a Null Poison and then none of the enemies use Poison anymore.) Any ideas about avoid this? Or is it not worth worrying about?

Perhaps you'd want to avoid developing A.I so advanced that becomes invincible. I mean, it's good for bosses and other major enemies but not so much for random encounters. Unless you're planning to give players a very hard time, that's it.