update_calendar_event

SERVERLocal SOURCElocal-mcp

Medium RISK CLASS

Category Write

Parameters 81 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/com-local-mcp-local-mcp/update-calendar-event.md

WHAT IT DOES

What update_calendar_event does on Local

AI agents use update_calendar_event to create or update resources in Local, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Local environment.

Parameter	Type	Required	Description
`span`	string	—	For recurring events: 'this' (default) or 'future'
`notes`	string	—	New notes — pass empty string to clear (optional)
`title`	string	—	New title (optional)
`confirm`	boolean	—	Must be true to apply changes
`end_date`	string	—	New end datetime ISO 8601 (optional)
`event_id`	string	Yes	Event identifier from list_calendar_events
`location`	string	—	New location — pass empty string to clear (optional)
`start_date`	string	—	New start datetime ISO 8601 (optional)

Parameters from the server's own tool schema.

RISK

Why update_calendar_event is rated Medium

This tool modifies calendar data (updates events) but does not delete, destroy, or permanently remove data. Updates are reversible—modified events can be edited again or reverted. The blast radius is moderate: a misdirected agent could alter meeting times, locations, or details affecting the user's schedule and potentially impacting others invited to those events.

From the tool's definition Tool name is 'update_calendar_event' and description explicitly states it 'Updates an existing event' by modifying specified fields. This is a reversible modification operation.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs update_calendar_event safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Local, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For update_calendar_event, this is the rule to start with:

update_calendar_event Rate-limited

update_calendar_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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_calendar_event": {
      "limits": [
        {
          "counter": "update_calendar_event_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Local, apply this rule, and every update_calendar_event call is checked against it from then on.

FAQ

Questions about update_calendar_event

What does the update_calendar_event tool do? +

Updates an existing event in the Mac's Calendar app (Calendar.app) by ID. Pass only the fields you want to change — unspecified fields are left as-is. Get the event_id from list_calendar_events. For Microsoft 365 use the m365 calendar tools instead. It is categorised as a Write tool in the Local MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does update_calendar_event accept? +

update_calendar_event accepts 8 parameters: span, notes, title, confirm, end_date, event_id, location, start_date. Required: event_id. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on update_calendar_event? +

Register the Local MCP server in PolicyLayer and add a rule for update_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 Local. Nothing to install.

What risk level is update_calendar_event? +

update_calendar_event is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit update_calendar_event? +

Yes. Add a rate_limit block to the update_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.

How do I block update_calendar_event completely? +

Set action: deny in the PolicyLayer policy for update_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.

What MCP server provides update_calendar_event? +

update_calendar_event is provided by the Local MCP server (local-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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