when your agent eval catches a failure what do u actually do next?

been talking to a bunch of people building agents and something ive noticed is a lot of teams already have their own evals, tracing, monitoring, internal tools etc so im curious what happens after all that shit tells u something went wrong like think abt the last real incident u had, not hypothetically did ur eval actually get u close to the problem or did it basically just tell u "yeah this is broken" and then u still had to go dig through everything? did u end up reading through traces manually comparing it to another run replaying it checking tool args/state/prompts writing some random script to narrow it down adding more logs pulling someone else in or does ur current setup actually get u to the issue pretty quickly? also how long did that whole thing take? im mostly talking abt the annoying cases where the agent technically finishes but the actual behavior/output is wrong, not like an obvious crash or 500 one thing ive struggled with personally is how much to trust a "good" comparison run sometimes it makes the important difference really obvious, but other times the reference run has its own variation and suddenly ur investigating a difference that might not actually mean anything especially when the finding literally only exists because the two runs are different so ive started treating the comparison more like another piece of evidence instead of ground truth curious how other people handle this when something goes wrong, what evidence usually gets u to the actual issue fastest and what part of the investigation is still manual? lmk ty