restart_device · UniFi MCP Server MCP: Risk & Policy

WHAT IT DOES

What restart_device does on UniFi MCP Server

AI agents invoke restart_device to trigger actions in UniFi MCP Server. 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 restart_device needs a policy

This tool executes a command on network infrastructure (device restart) rather than merely reading data or performing reversible modifications. While not destructive (data is not deleted/overwritten), restarting a device is an active operation that interrupts service and could impact network availability depending on which device is targeted.

From the tool's definition Tool description states 'Restart a UniFi network device by its MAC address'. Restart is an external operation that triggers a device action whose effects depend on the MAC address argument provided.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

restart_device Rate-limited

restart_device 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": {
    "restart_device": {
      "limits": [
        {
          "counter": "restart_device_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 UniFi MCP Server, so you can run agents against it safely.

FAQ

Questions about restart_device

What does the restart_device tool do? +

Restart a UniFi network device by its MAC address. It is categorised as a Execute tool in the UniFi MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on restart_device? +

Register the UniFi MCP Server MCP server in PolicyLayer and add a rule for restart_device: 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 UniFi MCP Server. Nothing to install.

What risk level is restart_device? +

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

Can I rate-limit restart_device? +

Yes. Add a rate_limit block to the restart_device 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 restart_device completely? +

Set action: deny in the PolicyLayer policy for restart_device. 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 restart_device? +

restart_device is provided by the UniFi MCP Server MCP server (nntkio/unifimcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.