create_recurring_event · Calendar MCP: Risk & Policy

WHAT IT DOES

What create_recurring_event does on Calendar Mcp

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

WHY IT NEEDS A POLICY

Why create_recurring_event needs a policy

This tool creates new calendar events with recurring patterns. Creation is a Write operation—it modifies calendar state but is reversible through deletion. Severity is medium because misuse could fill calendars with unwanted recurring events, but the impact is limited to calendar data and reversible.

From the tool's definition Tool name is 'create_recurring_event' and description states 'Create a recurring event'. Server description confirms 'CRUD operations' including event creation. The tool creates calendar entries that can be modified or deleted later.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_recurring_event Rate-limited

create_recurring_event 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_recurring_event": {
      "limits": [
        {
          "counter": "create_recurring_event_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 Calendar Mcp, so you can run agents against it safely.

FAQ

Questions about create_recurring_event

What does the create_recurring_event tool do? +

Create a recurring event. It is categorised as a Write tool in the Calendar Mcp 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_recurring_event? +

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

What risk level is create_recurring_event? +

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

Can I rate-limit create_recurring_event? +

Yes. Add a rate_limit block to the create_recurring_event 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_recurring_event completely? +

Set action: deny in the PolicyLayer policy for create_recurring_event. 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_recurring_event? +

create_recurring_event is provided by the Calendar MCP server (ydrogen/calendar-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.