The easiest way to find the WS where this attribute is missing is to search for purpose attribute and place it next to it.

Already declared in core_course_get_contents inside modules.

Missing on:

• block_recentlyaccesseditems_get_recent_items
• core_calendar_get_action_events_by_course
• core_calendar_get_action_events_by_courses
• core_calendar_get_action_events_by_timesort
• core_calendar_get_calendar_day_view
• core_calendar_get_calendar_event_by_id
• core_calendar_get_calendar_monthly_view
• core_calendar_get_calendar_upcoming_view
• core_calendar_submit_create_update_form
• core_calendar_update_event_start_day

There's also a typo on the WS core_calendar_get_action_events_by_timesort description "Get calendar action events by tiemsort"