AI agents call delete-events-by-keyword to permanently remove resources in macOS Calendar MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
The tool permanently deletes calendar events without the ability to undo the action through the tool interface itself. While the blast radius is limited to calendar data (not system-wide or financial), the irreversible nature of deletion and potential for bulk removal via keyword matching (affecting multiple events) classifies this as Destructive rather than Write.
From the tool's definition Tool name contains 'delete' and description states '根据关键词删除事件' (delete events by keyword). This irreversibly removes calendar events matching specified criteria.
Documented attack patterns abuse exactly the kind of access delete-events-by-keyword gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and macOS Calendar MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for delete-events-by-keyword:
{
"version": "1",
"default": "deny",
"hide": [
"delete-events-by-keyword"
]
}delete-events-by-keyword 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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根据关键词删除事件. It is categorised as a Destructive tool in the macOS Calendar MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the macOS Calendar MCP Server MCP server in PolicyLayer and add a rule for delete-events-by-keyword: 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 macOS Calendar MCP Server. Nothing to install.
delete-events-by-keyword 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-events-by-keyword 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-events-by-keyword. 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-events-by-keyword is provided by the macOS Calendar MCP Server MCP server (xybstone/macos-calendar-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from macOS Calendar MCP Server, 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.
8 macOS Calendar MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.