create_calendar · MCP Apple Reminders MCP: Risk & Policy

WHAT IT DOES

What create_calendar does on MCP Apple Reminders

AI agents use create_calendar 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_calendar needs a policy

Creating a calendar is a write operation that adds data reversibly. While the empty description limits certainty about exact behavior, the name and the server's stated create capability suggest this tool creates a new calendar entity. Severity is medium because accidental calendar creation could clutter the user's system but is easily undone via deletion.

From the tool's definition Tool name is 'create_calendar'; server description indicates the MCP server exposes Apple Reminders with capabilities including 'create...of reminders and lists.' The tool name suggests calendar creation, which would be a reversible write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_calendar Rate-limited

create_calendar 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_calendar": {
      "limits": [
        {
          "counter": "create_calendar_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_calendar

What does the create_calendar tool do? +

create_calendar. 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_calendar? +

Register the MCP Apple Reminders MCP server in PolicyLayer and add a rule for create_calendar: 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_calendar? +

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

Can I rate-limit create_calendar? +

Yes. Add a rate_limit block to the create_calendar 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_calendar completely? +

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

create_calendar 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.