create_entities · MCP Memory Server MCP: Risk & Policy

WHAT IT DOES

What create_entities does on MCP Memory Server

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

WHY IT NEEDS A POLICY

Why create_entities needs a policy

This tool creates new entities in a knowledge graph, which modifies the graph structure reversibly. If misused by an agent, it could pollute the knowledge graph with incorrect or malicious entities, but the effect is reversible via deletion tools. This is characteristic of Write-category operations—data modification without permanent, irreversible consequences.

From the tool's definition Tool name: 'create_entities'; description: 'Create multiple new entities in the knowledge graph'. The verb 'create' directly indicates data creation, which is a Write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_entities Rate-limited

create_entities 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_entities": {
      "limits": [
        {
          "counter": "create_entities_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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

FAQ

Questions about create_entities

What does the create_entities tool do? +

Create multiple new entities in the knowledge graph. It is categorised as a Write tool in the MCP Memory Server 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_entities? +

Register the MCP Memory Server MCP server in PolicyLayer and add a rule for create_entities: 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 MCP Memory Server. Nothing to install.

What risk level is create_entities? +

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

Can I rate-limit create_entities? +

Yes. Add a rate_limit block to the create_entities 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_entities completely? +

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

create_entities is provided by the MCP Memory Server MCP server (stevenwangler/mcp-memory-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.