Part 1 of this series made the case that AI observability is not just another dashboard problem. Once an agent is in production, the question is no longer can it respond; the question is whether it continues to respond accurately, safely, efficiently, and consistently as models evolve, prompts change, retrieval indexes drift, and real-world traffic exposes edge cases you never saw in test. That is why Microsoft Foundry’s observability story is built around three connected disciplines evaluation, monitoring, and tracing rather than traditional uptime metrics alone.