Every agent samples, at most every ten seconds: nvidia-smi's temperature, HBM temperature, power draw, enforced limit and throttle reasons per GPU; hwmon's CPU package and board inlet temperatures; and CPU package power from RAPL's energy counters. Sent with heartbeats, published as metrics and shown on the node page; unmeasured sensors are absent, never zero. Observe-only, step 0 of docs/facility-aware-placement.md, which now describes the agent source and what these readings can and cannot say. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>