What the agent does

Guest deployment: hostname, domain join, local admins and workflow steps, robust across reboots.
Remote commands, the guest's scheduled tasks, and disk-usage scans.
Live telemetry: heartbeat, CPU, memory and per-volume disk usage, and the real power state. CPU, memory and disk figures for a VM come only from its agent.
Rolling log files on the guest for troubleshooting.

The Fleet page

One live row per agent: online state, agent ID, hostname, linked VM, OS, agent version, IP, vCPU, RAM, CPU and memory, uptime and last seen.
Search by ID, hostname, IP or VM; filter by status, VM link, OS family and agent version. Version counts make rollout progress easy to follow.
The page needs cluster.view, which shows all agents.

Start the agent in a guest and it registers itself; there is no per-host configuration.
It enrolls once with the template's bootstrap secret and signs in with its own key from then on. That secret only enrolls — it can't act as the portal.
Reinstalled the agent on the same VM? Its new key is refused until you Offboard the old enrollment in Fleet; it then registers again on its own.
Agents are linked to their VM through the VM's SMBIOS UUID, which the portal sets at provisioning time. VMs created by the portal link automatically.
An unlinked agent usually means the UUID doesn't match, typical for machines cloned outside the portal.

The portal hosts the current agent release. Update agent in the row menu (agent.update, online agents) tells an agent to update now.
Agents also check for a newer version when they start and once a day.
The agent verifies the release's signature and checksum before replacing itself, then restarts its service.

Action	Effect
Delete agent	Removes the entry from the fleet list. A still-connected agent reappears with its next heartbeat. Needs vm.delete.
Offboard agent	Revokes the agent's enrollment, clears pending provisioning jobs and unlinks the VM. The agent must register again to return. Press-and-hold.

Neither action uninstalls the agent. Deleting a VM offboards its agent automatically.