foundry_anvil_stop · HashPilot MCP: Risk & Policy

WHAT IT DOES

What foundry_anvil_stop does on HashPilot

AI agents invoke foundry_anvil_stop to trigger actions in HashPilot. 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 foundry_anvil_stop needs a policy

This tool executes a command to terminate a service. While not destructive to persistent data and not read-only, it is an Execute-category action because it triggers an external operation with side effects (halting blockchain infrastructure). The severity is medium: stopping a local node disrupts operations but is reversible (the node can be restarted).

From the tool's definition Tool description states 'Stop the running Anvil local node' — this triggers an external operation (terminating a process) whose effects depend on runtime state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

foundry_anvil_stop Rate-limited

foundry_anvil_stop 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": {
    "foundry_anvil_stop": {
      "limits": [
        {
          "counter": "foundry_anvil_stop_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 HashPilot, so you can run agents against it safely.

FAQ

Questions about foundry_anvil_stop

What does the foundry_anvil_stop tool do? +

Stop the running Anvil local node. It is categorised as a Execute tool in the HashPilot MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on foundry_anvil_stop? +

Register the HashPilot MCP server in PolicyLayer and add a rule for foundry_anvil_stop: 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 HashPilot. Nothing to install.

What risk level is foundry_anvil_stop? +

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

Can I rate-limit foundry_anvil_stop? +

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

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

foundry_anvil_stop is provided by the HashPilot MCP server (justmert/hashpilot). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.