create_event · Calendar MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_event does on Calendar MCP Server

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

WHY IT NEEDS A POLICY

Why create_event needs a policy

The tool creates new calendar entries, which is a Write operation (creates/modifies data reversibly). Severity is medium because misuse could spam calendars, create fraudulent meetings with attendees, or disrupt scheduling, but the impact is limited to calendar data and can be undone by deletion. It does not execute arbitrary code, delete data irreversibly, or move money, so more severe categories do not apply.

From the tool's definition Tool name 'create_event' and description states it 'Create a new calendar event' with support for attendees, recurrence, and online meetings. This is a reversible data modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_event Rate-limited

create_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_event": {
      "limits": [
        {
          "counter": "create_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 Server, so you can run agents against it safely.

FAQ

Questions about create_event

What does the create_event tool do? +

Create a new calendar event. Supports attendees, recurrence, online meetings (Teams/Meet), and custom reminders. It is categorised as a Write tool in the Calendar MCP Server 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_event? +

Register the Calendar MCP Server MCP server in PolicyLayer and add a rule for create_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 Server. Nothing to install.

What risk level is create_event? +

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

Can I rate-limit create_event? +

Yes. Add a rate_limit block to the create_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_event completely? +

Set action: deny in the PolicyLayer policy for create_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_event? +

create_event is provided by the Calendar MCP Server MCP server (rauf543/calendar-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.