create_relations · Mcp Brain MCP: Risk & Policy

WHAT IT DOES

What create_relations does on Mcp Brain

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

WHY IT NEEDS A POLICY

Why create_relations needs a policy

This tool creates new connections/relationships between existing entities in a persistent knowledge graph. Creating relations modifies the graph structure reversibly (relations can be deleted or updated later) without irreversibly destroying data or executing arbitrary code.

From the tool's definition Tool name 'create_relations' and description 'Create connections between memories in the brain' indicate the tool creates or adds new relational data to a knowledge graph.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_relations Rate-limited

create_relations 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_relations": {
      "limits": [
        {
          "counter": "create_relations_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 Mcp Brain, so you can run agents against it safely.

FAQ

Questions about create_relations

What does the create_relations tool do? +

Create connections between memories in the brain\. It is categorised as a Write tool in the Mcp Brain 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_relations? +

Register the Mcp Brain MCP server in PolicyLayer and add a rule for create_relations: 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 Brain. Nothing to install.

What risk level is create_relations? +

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

Can I rate-limit create_relations? +

Yes. Add a rate_limit block to the create_relations 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_relations completely? +

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

create_relations is provided by the Mcp Brain MCP server (touristshaun/mcp-brain). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.