Tracing Agent Harness Behavior with NVIDIA NeMo Relay

NVIDIA’s tutorial shows NeMo Relay as a common observability layer capturing ordered lifecycle events and structured trajectories for agent runs. Hermes Agent ships native integration producing ATOF event streams, ATIF step-by-step trajectories, and OpenTelemetry/OpenInference spans viewable in tools like Arize Phoenix.

Examples include a terminal-tool task verified to VALUE=42 with zero tool errors, and a multi-tool research task ending in “COLT 2026.” A ToolPerf case study across 108 runs found a Qwen Coder 30B harness revision recovered more tasks but increased calls, data, and latency — proof that success rate alone hides cost.

We’re making this required reading for anyone shipping agents after a summer of swarming failures.

Correct finals with wasteful paths are how bills explode and retries cascade into incidents. Shared trace formats beat screenshot debugging. Useful agent platforms will compete on observability as much as model IQ.

I’m watching whether ATOF/ATIF become cross-vendor habits or stay NVIDIA/Hermes-centric. The ToolPerf lesson — better recovery, worse efficiency — is the honest eval posture we want industry-wide.

We’ll push teams to gate harness merges on trace diffs, not vibes. If you can’t see the trajectory, you don’t control the agent.

NVIDIA Technical Blog tutorial on NeMo Relay + Hermes Agent, September 30, 2026.