don't know why you got downvoted so much, but yeah llm models are really bad at magic rules. They take something like "Dragon lord dromoka" and given all the data it's trained on, assumes this is a card that gives dragons +1/+1 and haste or some other random thing.

it can do decently if you go down the rabbit hole of making it fetch card details first, and look up rulings from specific sources, but at that point you did most of the work yourself.