AI agents call delete_event to permanently remove resources in Outlook Calendar MCP — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
This tool permanently removes calendar events without the ability to restore them. Deletion is irreversible and represents data destruction. While the blast radius is limited to calendar events (not system-wide), accidental or malicious deletion of important meetings could cause significant disruption to productivity and commitments.
From the tool's definition Tool name 'delete_event' and description 'Delete a calendar event by its ID' explicitly state irreversible deletion of calendar data.
Documented attack patterns abuse exactly the kind of access delete_event gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Outlook Calendar MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for delete_event:
{
"version": "1",
"default": "deny",
"hide": [
"delete_event"
]
}delete_event disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.
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Delete a calendar event by its ID. It is categorised as a Destructive tool in the Outlook Calendar MCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Outlook Calendar MCP server in PolicyLayer and add a rule for delete_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 Outlook Calendar MCP. Nothing to install.
delete_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 delete_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 delete_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.
delete_event is provided by the Outlook Calendar MCP server (merajmehrabi/outlook_calendar_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Outlook Calendar MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
7 Outlook Calendar MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.