STEP 1 - ALWAYS CALL THIS FIRST. Lists all calendars in the user's Fastmail account. Returns an array of calendars with displayName (human-readable name like "Work", "Personal", "Family"), url (required for other operations), and timezone. You MUST call this before list_events, create_event, update_event, or delete_event to get the calendar URL. Look at the displayName to identify which calendar the user wants (e.g., "Work" for work schedule, "Personal" for personal events).

STEP 2 - Get events from a calendar. PREREQUISITE: You must first call list_calendars to get the calendarUrl. Returns events within the specified date range. Each event contains: url (needed for update/delete), etag (needed for delete), and data (iCalendar format with SUMMARY=title, DTSTART=start time, DTEND=end time, LOCATION, DESCRIPTION). Parse the iCalendar data to show event details to the user.

Get parsed details of a specific event. PREREQUISITE: You must first call list_calendars, then list_events to get the eventUrl. Returns structured event data (title, start, end, location, description) instead of raw iCalendar format.

Create a new calendar event. PREREQUISITE: You must first call list_calendars to get the calendarUrl. Creates an event with the specified title, times, and optional description/location.

Modify an existing event. PREREQUISITE: You must first call list_calendars, then list_events to get the eventUrl. Only include fields you want to change; omitted fields stay the same.

PERMANENTLY DELETE an event. PREREQUISITE: You must first call list_calendars, then list_events to get both the eventUrl AND etag. WARNING: This cannot be undone. Always confirm with the user before deleting.