cancel-calendar-event
This action allows the organizer of a meeting to send a cancellation message and cancel the event. The action moves the event to the Deleted Items folder. The organizer can also cancel an occurrence of a recurring meeting by providing the occurrence event ID. An attendee calling this action gets ...
This record as markdown: /tools/jo3zik-ms-365-mcp-server/cancel-calendar-event.md
What cancel-calendar-event does on Ms 365
AI agents call cancel-calendar-event to permanently remove resources in Ms 365, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
| Parameter | Type | Required | Description |
|---|---|---|---|
body | object | Yes | |
confirm | boolean | — | For destructive operations when the confirm gate is enabled (MS365_MCP_REQUIRE_CONFIRM=true; off by default). Set to true only after the user has explicitly app |
eventId | string | Yes | Value for the 'eventId' path segment. Pass it under the name 'eventId', not as 'id'. Use the 'id' field of the event object as returned by Microsoft Graph. |
includeHeaders | boolean | — | Include response headers (including ETag) in the response metadata |
excludeResponse | boolean | — | Exclude the full response body and only return success or failure indication |
Parameters from the server's own tool schema.
Why cancel-calendar-event is rated Critical
An AI agent that decides to call cancel-calendar-event doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from Ms 365 is gone. There is no undo for destructive operations.
Risk signalsAccepts raw HTML/template content (body)
Attacks that exploit this kind of access
The rule that runs cancel-calendar-event safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Ms 365, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For cancel-calendar-event, this is the rule to start with:
cancel-calendar-event is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Ms 365, apply this rule, and every cancel-calendar-event call is checked against it from then on.
Questions about cancel-calendar-event
This action allows the organizer of a meeting to send a cancellation message and cancel the event. The action moves the event to the Deleted Items folder. The organizer can also cancel an occurrence of a recurring meeting by providing the occurrence event ID. An attendee calling this action gets an error (HTTP 400 Bad Request), with the following error message: 'Your request can't be completed. You need to be an organizer to cancel a meeting.' This action differs from Delete in that Cancel is available to only the organizer, and lets the organizer send a custom message to the attendees about the cancellation. 💡 TIP: Cancels a meeting (organizer only) and sends a cancellation message to all attendees. Body: { Comment (optional string, custom message) }. Use this instead of delete-calendar-event when you want attendees to see 'Canceled' in their calendar. Attendees calling this get HTTP 400 — they should use decline-calendar-event instead. It is categorised as a Destructive tool in the Ms 365 MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
cancel-calendar-event accepts 5 parameters: body, confirm, eventId, includeHeaders, excludeResponse. Required: body, eventId. The full parameter table on this page comes from the server's own tool schema.
Register the Ms 365 MCP server in PolicyLayer and add a rule for cancel-calendar-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 Ms 365. Nothing to install.
cancel-calendar-event is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the cancel-calendar-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.
Set action: deny in the PolicyLayer policy for cancel-calendar-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.
cancel-calendar-event is provided by the Ms 365 MCP server (@jo3zik/ms-365-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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