Cancel a Cal.com booking and notify the attendee. Side effect: sends a cancellation email to all participants. This action cannot be undone.
AI agents call cal_cancel_booking to permanently remove resources in Access — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
While the tool involves Write-like operations (modifying calendar state), the combination of irreversibility ('cannot be undone'), data destruction (removing a booking), and inability to restore the original state places this in Destructive rather than Write.
From the tool's definition Tool description states 'Cancel a Cal.com booking' and explicitly declares 'This action cannot be undone.' Cancellation of bookings is an irreversible operation that destroys calendar data and commitment records.
Attacks that exploit this kind of access
Cancel a Cal.com booking and notify the attendee. Side effect: sends a cancellation email to all participants. This action cannot be undone. It is categorised as a Destructive tool in the Access MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Access MCP server in PolicyLayer and add a rule for cal_cancel_booking: 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 Access. Nothing to install.
cal_cancel_booking 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 cal_cancel_booking 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 cal_cancel_booking. 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.
cal_cancel_booking is provided by the Access MCP server (scottpedia0/access). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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