restart_dns · Mcp Pihole MCP: Risk & Policy

WHAT IT DOES

What restart_dns does on Mcp Pihole

AI agents invoke restart_dns to trigger actions in Mcp Pihole. 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_dns needs a policy

This tool executes a restart command on the DNS resolver, which is an external operation whose effects depend on timing and system state. While not destructive (the service remains intact) or financial, restarting a DNS resolver can disrupt network connectivity for all devices relying on Pi-hole for DNS resolution.

From the tool's definition Tool name 'restart_dns' and description 'Restart the Pi-hole DNS resolver' indicate triggering an external operation that restarts a critical network service.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

restart_dns Rate-limited

restart_dns 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_dns": {
      "limits": [
        {
          "counter": "restart_dns_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 Mcp Pihole, so you can run agents against it safely.

FAQ

Questions about restart_dns

What does the restart_dns tool do? +

Restart the Pi-hole DNS resolver. It is categorised as a Execute tool in the Mcp Pihole 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_dns? +

Register the Mcp Pihole MCP server in PolicyLayer and add a rule for restart_dns: 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 Mcp Pihole. Nothing to install.

What risk level is restart_dns? +

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

Can I rate-limit restart_dns? +

Yes. Add a rate_limit block to the restart_dns 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_dns completely? +

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

restart_dns is provided by the Mcp Pihole MCP server (obrien-matthew/mcp-pihole). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.