gateway.restart_server

THE RISK

High Risk

Why gateway.restart_server needs a policy

This tool executes a restart operation on a downstream MCP server, which is an external action with side effects. It does not retrieve data (Read), create/modify reversibly (Write), delete irreversibly (Destructive), or move money (Financial). Restarting a server can disrupt services and dependent operations, making it Execute rather than lower-impact categories.

From the tool's definition Tool description: 'Restart a known downstream MCP server without changing persistent config.' The verb 'Restart' indicates triggering an external operation (server restart) whose effects depend on which server is targeted via arguments.

Documented attack patterns abuse exactly the kind of access gateway.restart_server gives an agent:

POLICY

How to control gateway.restart_server

PolicyLayer is an MCP gateway — it sits between your AI agents and PMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for gateway.restart_server:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "gateway.restart_server": {
      "limits": [
        {
          "counter": "gateway.restart_server_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

gateway.restart_server 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.

Create a free account and register PMCP — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More PMCP tools

Destructive gateway.disconnect_server Disconnect a running downstream MCP server without changing persistent config. Execute gateway.tasks_cancel Cancel a downstream MCP task by opaque task ID. Execute gateway.connect_server Connect or start a known downstream MCP server by name. Execute gateway.invoke Invoke a tool on a downstream MCP server. Execute gateway.provision Provision (install and start) a specific MCP server from the manifest. Execute gateway.refresh Reload backend MCP server configurations and reconnect. Execute gateway.request_capability Find and auto-provision the right tool for a task — describe what you need in natural lang Write gateway.cancel Cancel a pending tool invocation.

All 26 PMCP tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in PMCP → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about gateway.restart_server

What does the gateway.restart_server tool do? +

Restart a known downstream MCP server without changing persistent config. It is categorised as a Execute tool in the PMCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on gateway.restart_server? +

Register the P MCP server in PolicyLayer and add a rule for gateway.restart_server: 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 PMCP. Nothing to install.

What risk level is gateway.restart_server? +

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

Can I rate-limit gateway.restart_server? +

Yes. Add a rate_limit block to the gateway.restart_server 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 gateway.restart_server completely? +

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

gateway.restart_server is provided by the P MCP server (viperjuice/pmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every PMCP tool call.

Start from PMCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →