Calendar Event Visibility vs Availability: A Guide for AI Agents

A private event can still block your time. A public event can leave you available. Google Calendar stores those decisions in two different event fields, and an AI agent should never treat them as synonyms.

Two separate controls

visibilitycontrols how event details are exposed according to the calendar's sharing rules. transparency controls whether the event blocks time for free/busy purposes. The Google Calendar Events resource documents opaque as busy and transparentas free. CalendarMCP exposes both on create_event and update_event.

Pick the right combination

• Personal appointment: private visibility, busy availability.
• Travel reminder that should not block meetings: private visibility, free availability.
• Team office-hours block: decide both according to your calendar-sharing policy.

The labels above are examples, not universal defaults. A shared calendar can have its own access rules, so preview the target calendar and confirm the intended audience before writing sensitive titles or descriptions.

Prompt pattern

“Create a private, busy appointment on my personal calendar from 2:00 to 2:30 PM Pacific. Show me the account, calendar, timezone, visibility, and availability before you save it.”

Sources: Google Calendar Events resource and CalendarMCP tool documentation.