proxmox_stop_vm · Homelab MCP: Risk & Policy

WHAT IT DOES

What proxmox_stop_vm does on Homelab

AI agents invoke proxmox_stop_vm to trigger actions in Homelab. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why proxmox_stop_vm needs a policy

This tool executes a command against infrastructure (Proxmox hypervisor) to change the state of a VM/container. While graceful shutdown is reversible (VMs can be restarted), the action itself is Execute-class because it runs an external operation whose impact depends on arguments. It is not Destructive because shutdown is not irreversible—containers and VMs can be restarted.

From the tool's definition The tool performs 'Stop (graceful shutdown) a VM or LXC container' — this is an operational action that triggers external system behavior (halting a running virtual machine), whose effects depend on which VMID argument is provided.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

proxmox_stop_vm Rate-limited

proxmox_stop_vm stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "proxmox_stop_vm": {
      "limits": [
        {
          "counter": "proxmox_stop_vm_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Homelab, so you can run agents against it safely.

FAQ

Questions about proxmox_stop_vm

What does the proxmox_stop_vm tool do? +

Stop (graceful shutdown) a VM or LXC container by its VMID. It is categorised as a Execute tool in the Homelab MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on proxmox_stop_vm? +

Register the Homelab MCP server in PolicyLayer and add a rule for proxmox_stop_vm: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Homelab. Nothing to install.

What risk level is proxmox_stop_vm? +

proxmox_stop_vm is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit proxmox_stop_vm? +

Yes. Add a rate_limit block to the proxmox_stop_vm rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block proxmox_stop_vm completely? +

Set action: deny in the PolicyLayer policy for proxmox_stop_vm. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides proxmox_stop_vm? +

proxmox_stop_vm is provided by the Homelab MCP server (nainounen/homelab-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.