create_group · MCP Apple Reminders MCP: Risk & Policy

WHAT IT DOES

What create_group does on MCP Apple Reminders

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

WHY IT NEEDS A POLICY

Why create_group needs a policy

The tool creates a new organizational group for reminders. This is a Write operation because it creates data (a new group) that can be reversed by deletion. Severity is low because creating a reminder group has minimal blast radius—it does not delete data, execute external code, or involve financial transactions.

From the tool's definition Tool name 'create_group' combined with server description stating the MCP server 'exposes Apple Reminders to AI clients, enabling create, read, update, delete, search, and organization of reminders and lists.' The tool creates a new reminder group/list, which…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_group Rate-limited

create_group 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_group": {
      "limits": [
        {
          "counter": "create_group_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 Apple Reminders, so you can run agents against it safely.

FAQ

Questions about create_group

What does the create_group tool do? +

create_group. It is categorised as a Write tool in the MCP Apple Reminders 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_group? +

Register the MCP Apple Reminders MCP server in PolicyLayer and add a rule for create_group: 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 Apple Reminders. Nothing to install.

What risk level is create_group? +

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

Can I rate-limit create_group? +

Yes. Add a rate_limit block to the create_group 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_group completely? +

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

create_group is provided by the MCP Apple Reminders MCP server (rex/mcp-apple-reminders). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.