Basically wondering if someone else has already done the calculations to work out when a lower damage attack with the Agile trait is better than a higher damage attack without it. Is there a good rule of thumb here?

The specific scenario I'm looking at is one of my players' Badger animal companions, which can take 2 actions. If it's in a situation where both those actions are going to be attacks, is it better to bite twice (1d8 without Agile) or bite and then claw* (1d6 with Agile). I am mainly wondering about the general rule of thumb though, if there is one.

* I'm assuming my reading on the rules here is right. If the first attack is not Agile, but the second one is, that's still only the -4 penalty, right?