ListCalendarsCopy Anchor Link

List the calendars the user can see across their connected inboxes, with each calendar's calendarId, display name, syncing inbox address, provider, capabilities, and whether it is primary, writable and part of the user's busy time.

Not every calendar here is the user's. emailAddress is the account syncing a calendar, so a colleague's calendar reports the user's own address, and being writable or not primary proves nothing either way. contributesToAvailability marks the calendars that are the user's schedule. Call any other by its name, say whose it is when the name shows that, and otherwise say you cannot tell.

Use this before CreateCalendarEvent when the user wants an event on a specific non-default calendar (e.g. "add it to my work calendar") so you can pass the exact calendarId. Most users have a single primary calendar, in which case CreateCalendarEvent targets it by default and you do not need this tool unless choosing conference or other provider-dependent behavior. Check capabilities before requesting a conference, removing one, or using custom recurrence. An empty result means no calendar is connected.