calendar_create_calendar · M365 MCP: Risk & Policy

WHAT IT DOES

What calendar_create_calendar does on M365

AI agents use calendar_create_calendar to create or update resources in M365 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your M365 environment.

WHY IT NEEDS A POLICY

Why calendar_create_calendar needs a policy

Creating a calendar is a reversible write operation that modifies a user's organizational structure within Microsoft 365. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), or move money (would be Financial). However, calendar creation could affect calendar sharing, visibility, and organizational workflows if misused by an AI agent, warranting a medium severity rating.

From the tool's definition Tool name 'calendar_create_calendar' indicates it creates a new calendar object. The empty description provides no additional details, but the verb 'create' paired with 'calendar' clearly indicates data creation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

calendar_create_calendar Rate-limited

calendar_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": {
    "calendar_create_calendar": {
      "limits": [
        {
          "counter": "calendar_create_calendar_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches M365, so you can run agents against it safely.

FAQ

Questions about calendar_create_calendar

What does the calendar_create_calendar tool do? +

calendar_create_calendar. It is categorised as a Write tool in the M365 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on calendar_create_calendar? +

Register the M365 MCP server in PolicyLayer and add a rule for calendar_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 M365. Nothing to install.

What risk level is calendar_create_calendar? +

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 calendar_create_calendar? +

Yes. Add a rate_limit block to the calendar_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 calendar_create_calendar completely? +

Set action: deny in the PolicyLayer policy for calendar_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 calendar_create_calendar? +

calendar_create_calendar is provided by the M365 MCP server (robin-collins/m365-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.