update_record · Pg Mnemosyne MCP: Risk & Policy

WHAT IT DOES

What update_record does on Pg Mnemosyne

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

WHY IT NEEDS A POLICY

Why update_record needs a policy

This tool modifies data in a PostgreSQL database. While it creates no new permanent records (Write) rather than deleting them (Destructive), it can alter existing data in ways that may have significant business impact depending on what records are modified.

From the tool's definition Tool description states it 'Updates a record in the database by its ID', which is a modification operation. The mechanism is reversible (updates can be undone with subsequent updates), distinguishing it from destructive operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_record Rate-limited

update_record 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": {
    "update_record": {
      "limits": [
        {
          "counter": "update_record_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 Pg Mnemosyne, so you can run agents against it safely.

FAQ

Questions about update_record

What does the update_record tool do? +

Updates a record in the database by its ID. Only non-None fields will be updated. It is categorised as a Write tool in the Pg Mnemosyne MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_record? +

Register the Pg Mnemosyne MCP server in PolicyLayer and add a rule for update_record: 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 Pg Mnemosyne. Nothing to install.

What risk level is update_record? +

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

Can I rate-limit update_record? +

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

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

update_record is provided by the Pg Mnemosyne MCP server (janadasroor/pg-mnemosyne-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.