Agent observability vs application monitoring
By Matt Doughty, CEO & Co-Founder of Prefactor ·
Application monitoring tells you whether the service is healthy. Agent observability tells you whether the agent did the right thing — and lets you reconstruct how it decided. Teams running agents need both, and the gap between them is where agent incidents hide.
| Dimension | Agent observability | Application monitoring |
|---|---|---|
| Core question | Did the agent do the right thing? | Is the service up and fast? |
| Unit of analysis | Task: reasoning steps, tool calls, model calls | Request: latency, errors, throughput |
| Failure it catches | Confidently wrong actions with healthy metrics | Outages, slowdowns, error spikes |
| Primary consumers | Agent engineers, evaluators, auditors | SRE and on-call engineers |
| Data sensitivity | High — captures prompts, tool inputs/outputs | Lower — mostly metadata and metrics |
| Typical tooling | Tracing with agent span conventions, eval pipelines | APM, metrics, log aggregation |
The verdict
This is not a choice between two products but between two layers. Keep application monitoring for the infrastructure an agent runs on; add agent observability the moment an agent takes actions that matter, because that is the moment "the service is healthy" stops meaning "the agent is behaving." If budget forces sequencing, instrument the agent's tool calls first — that is where consequential actions happen and where post-incident questions land.