Since we're not passing any inputs to ListAccounts, it makes sense to use .run! instead of .run. If it failed, that would mean we probably messed up writing the interaction.

Rule of Repair: When you must fail, fail noisily and as soon as possible.

I always prefer strictness, bad behavior should be uncovered as soon as possible or you are effectively encouraging it, which means they'll soon be back asking why it doesn't work for X and Y. Fix the problem at the source. I don't really care, but IMHO doing this seems like a charitable thing but it's actually the opposite.