This card seems to do nothing as printed/pre-viewed here.

When a token is spent, the defender gets its produced effect. Is it supposed to be that the are you to somehow secretly choose a defense token and if the defender selects that token, its to be exhausted without any effects? If you declare the token, the defender can just not pick it. Or just choose a defense token to be discarded? Or what?

You would announce your selection when you exhaust the card. Everything in this game except facedown command dials and facedown damage cards is open information.

What this card allows you to do is for your opponent to make a bad choice. If they have one Evade token, and the Evade would really help them during the attack, declaring that token as the target of this card would mean that they either don't get to use the token (and thus preserve it) or get one final use (since it is discarded when spent instead). I see this being best combined with accuracy results on the dice: cancel all defense tokens but one with accuracy, and target the last token with this card, such that if they want to keep the token, they're taking full damage.

Thanks.

When I posted this, I was unclear of the different states of the defense token being ready, exhausted and spent (I was thinking the defense tokens acted like cards - because exhausted and spent, by definition, mean the same thing in dictionaries).

I'm thinking this could combo well with Overload Pulse. Overload Pulse (on a blue crit) normally forces them to use their defense tokens as they will be exhausted after the attack is resolved anyway but with the Agent they either lose 1 and exhaust all other tokens, or don't gain the benefit and exhaust them anyway.