AI agents use create-event to create or update resources in macOS Calendar MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your macOS Calendar MCP Server environment.
This tool creates new calendar events, which is a reversible modification of calendar data. It does not execute arbitrary code, delete data permanently, or involve financial transactions. The severity is medium because calendar event creation could be misused to flood a calendar, create misleading schedules, or spam notifications, but the impact is limited to calendar data that can be manually deleted or corrected.
From the tool's definition Tool name 'create-event' and description indicating creation of new events in macOS Calendar. Sibling tools include 'delete-events-by-keyword' and 'create-batch-events', confirming this server handles calendar data modification.
Documented attack patterns abuse exactly the kind of access create-event 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 create-event:
{
"version": "1",
"default": "deny",
"tools": {
"create-event": {
"limits": [
{
"counter": "create-event_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}create-event 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.
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在macOS日历中创建新事件. It is categorised as a Write tool in the macOS Calendar MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the macOS Calendar MCP Server MCP server in PolicyLayer and add a rule for create-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 macOS Calendar MCP Server. Nothing to install.
create-event is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the create-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 create-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.
create-event 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.
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8 macOS Calendar MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.