create_graph · Mnemosyne MCP: Risk & Policy

WHAT IT DOES

What create_graph does on Mnemosyne MCP

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

WHY IT NEEDS A POLICY

Why create_graph needs a policy

This tool creates new knowledge graphs, which is a reversible data creation operation (Write category). Severity is medium because creating knowledge graphs could consume resources, potentially duplicate or corrupt existing structures if misused by an agent without proper validation, but the action itself is reversible.

From the tool's definition Tool name 'create_graph' and description 'Create new knowledge graph' explicitly indicate creation of new data structures. The server description confirms it manages 'knowledge graphs' and supports 'graph operations'.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_graph Rate-limited

create_graph 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": {
    "create_graph": {
      "limits": [
        {
          "counter": "create_graph_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 Mnemosyne MCP, so you can run agents against it safely.

FAQ

Questions about create_graph

What does the create_graph tool do? +

Create new knowledge graph with title and optional description. It is categorised as a Write tool in the Mnemosyne MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_graph? +

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

What risk level is create_graph? +

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

Can I rate-limit create_graph? +

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

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

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