rename_machine · Mementos MCP: Risk & Policy

WHAT IT DOES

What rename_machine does on Mementos

AI agents use rename_machine to create or update resources in Mementos — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mementos environment.

WHY IT NEEDS A POLICY

Why rename_machine needs a policy

This tool modifies metadata (a machine name) reversibly. The change can be undone by renaming it back to the original name. It does not delete data (Destructive), execute external operations (Execute), create financial obligations (Financial), or merely retrieve data (Read). It performs a create/update operation on stored state, classifying it as Write.

From the tool's definition Tool name 'rename_machine' and description 'Rename a machine by its ID or current name' indicate modification of existing data (a machine's name attribute) without deletion or irreversible destruction.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

rename_machine Rate-limited

rename_machine stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "rename_machine": {
      "limits": [
        {
          "counter": "rename_machine_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about rename_machine

What does the rename_machine tool do? +

Rename a machine by its ID or current name. It is categorised as a Write tool in the Mementos MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on rename_machine? +

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

What risk level is rename_machine? +

rename_machine is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit rename_machine? +

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

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

rename_machine is provided by the Mementos MCP server (@hasna/mementos). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.