mementos_storage_pull · Mementos MCP: Risk & Policy

WHAT IT DOES

What mementos_storage_pull does on Mementos

AI agents use mementos_storage_pull 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 mementos_storage_pull needs a policy

This tool writes/imports data from a remote PostgreSQL source into the local database. It creates or modifies local records in bulk, which is a Write operation. Severity is high because pulling remote data could overwrite or significantly alter the local memory database used by AI agents, potentially corrupting agent state or introducing unintended data at scale.

From the tool's definition Pull remote PostgreSQL storage data into the local mementos database

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mementos_storage_pull Rate-limited

mementos_storage_pull 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": {
    "mementos_storage_pull": {
      "limits": [
        {
          "counter": "mementos_storage_pull_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 mementos_storage_pull

What does the mementos_storage_pull tool do? +

Pull remote PostgreSQL storage data into the local mementos database. 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 mementos_storage_pull? +

Register the Mementos MCP server in PolicyLayer and add a rule for mementos_storage_pull: 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 mementos_storage_pull? +

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

Can I rate-limit mementos_storage_pull? +

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

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

mementos_storage_pull 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.