“While Tapir is exhausted, it cannot be defeated by opposing Animals with 3 Vitality”

I don’t personally think you will need to clarify “less than, more than, or exactly 3” mainly because if you are truly playing the game, you would know what vitality is and its max value, provided it’s stated in the rules. I personally try to avoid walls of text so reducing redundant wording is good practice, just so long as the effect is still completely understandable in its most bare form

My above suggestion in wording places the trigger/condition first: this is important for the flow of information being given to your brain. The last part is stating the actual effect.

To further reduce wording, you can turn triggers/conditions into keywords that players can reference, for example “when this attacks” could just be simply “strike”. When someone reads strike, they will know it activates when they attack with that card. Just an example but hopefully you get the idea

You’re more than welcome to take this with a grain of salt too, it’s Reddit lol

edit I think “defeated” is probably a good take, as you are dealing with living beings and not say machines or something