How do we track whether the tariffs "worked"?

What metric should we be using to track whether the tariffs implemented by Trump have actually worked?

The message from this administration is that we need to endure these tough times so that we come out better in the end. What does that "better" look like? Where do we think we are headed, and what can we cite to prove that we got there?

Edit: I feel like I've gotten my fill from the left. I'd love to hear from the right. Please.