create_entity · Dbrain MCP: Risk & Policy

WHAT IT DOES

What create_entity does on Dbrain

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

WHY IT NEEDS A POLICY

Why create_entity needs a policy

This tool creates new entities in the dbrain's structured memory system, which is a reversible Write operation. It does not delete, execute code, or trigger external systems. The severity is low because entity creation in a memory system has minimal blast radius—entities can be updated or the references removed without cascading damage.

From the tool's definition Tool description explicitly states 'Create a new entity' and is used 'before remembering facts about something new.' The action is creating a new data record in persistent memory.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_entity Rate-limited

create_entity 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_entity": {
      "limits": [
        {
          "counter": "create_entity_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 Dbrain, so you can run agents against it safely.

FAQ

Questions about create_entity

What does the create_entity tool do? +

Create a new entity (project, person, system, event). Use this before remembering facts about something new. It is categorised as a Write tool in the Dbrain 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_entity? +

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

What risk level is create_entity? +

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

Can I rate-limit create_entity? +

Yes. Add a rate_limit block to the create_entity 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_entity completely? +

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

create_entity is provided by the Dbrain MCP server (ivncmp/dbrain). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.