Why does the Core tier only have three Calendar tools?

Deliberate design. Every registered tool consumes context window and adds a decision point for the model. Consolidating create/update/delete into manage_event keeps the core schema small without dropping any capability; availability queries and working-status events live in the Extended tier for agents that need them.

Can an assistant check availability before proposing a meeting time?

Yes — query_freebusy returns busy intervals for any set of calendars over a time window, so a scheduling agent can find a genuinely open slot across the whole team instead of guessing from one person’s calendar.

Can it see calendars shared with me, not just my own?

Yes. list_calendars returns every calendar the authenticated account can access, including shared team calendars, and get_events works against any of them by ID.

How do time ranges work for event queries?

get_events takes an explicit time window, so an assistant can ask for "this week", "next Tuesday 9–5", or a whole quarter and only pull the events that matter rather than paging through everything.

Google Calendar MCP Server

Consolidated event management plus availability and working-status control.

Quick start Jump to all 7 tools →

Calendar keeps its core deliberately lean. Three tools — list_calendars, get_events, and manage_event — cover the entire event lifecycle, because every extra tool definition costs context window and gives the model another wrong option to pick.

The Extended tier adds the scheduling-assistant layer: query_freebusy checks availability across calendars before proposing a time, create_calendar spins up secondary calendars, and manage_out_of_office and manage_focus_time control the working-status events that auto-decline conflicting meetings.

What you can ask

“What does my week look like? Flag anything that conflicts with the Thursday offsite”
“Create a 30-minute design sync every Tuesday at 10am and invite the team”
“Find an hour next week when the whole team is free, then block it as Focus Time”

All 7 Google Calendar MCP tools

Expand any tool for its full parameter list. Tiers control how many tools the server registers: start lean with --tool-tier core and step up to extended or complete when a workflow needs more.

list_calendars Core Lists calendars accessible to the authenticated user. 2

Parameter	Description
`max_results`	Maximum calendars to return in one page.
`page_token`	Token for the next page, taken from a previous response. Responses include a next page token whenever more calendars remain.

get_events Core Retrieves events for a calendar and time range. 6

Parameter	Description
`calendar_id`	Defaults to `primary`.
`time_min`	RFC3339 or date.
`time_max`	RFC3339 or date.
`max_results`	Maximum events to return.
`single_events`	Whether to expand recurring series into individual instances. Defaults to true. Set to false to retrieve recurring master events and their RFC 5545 recurrence rules.
`page_token`	Token for the next page, taken from a previous response. With `single_events` true, also pass the response's pagination `time_min` as `time_min` (even if you omitted it on the first call) and keep every other query parameter unchanged. Ignored when `event_id` is set.

manage_event Core Consolidated create, update, and delete event operations. 5

Parameter	Description
`action` required	`create`, `update`, or `delete`.
`event_id`	Required for `update` and `delete`.
`start_timezone`	IANA timezone for the start boundary, overriding the shared `timezone`.
`end_timezone`	IANA timezone for the end boundary, overriding the shared `timezone`. Use separate boundary zones for events such as flights whose departure and arrival have different local times.
`attachments`	Drive file IDs or share URLs to attach. On `update` the list replaces the event's existing attachments rather than adding to them, so pass the full set you want to keep.

create_calendar Extended Create a new secondary Google Calendar. 3

Parameter	Description
`summary` required	Name for the new calendar.
`description`	Optional calendar description.
`timezone`	IANA timezone (e.g., "America/New_York").

query_freebusy Extended Query free/busy information across one or more calendars. 5

Parameter	Description
`time_min` required	Start of the window (RFC3339).
`time_max` required	End of the window (RFC3339).
`calendar_ids`	Calendar IDs to query. Defaults to `primary`.
`group_expansion_max`	Maximum calendars to expand per group.
`calendar_expansion_max`	Maximum calendars for which to return busy information.

manage_out_of_office Extended Create, list, update, or delete Out of Office events. 9

Parameter	Description
`action` required	`create`, `list`, `update`, or `delete`.
`start_time`	Start time (required for `create`).
`end_time`	End time (required for `create`).
`summary`	Event title.
`auto_decline_mode`	How conflicting meetings are declined.
`decline_message`	Message sent with auto-declines.
`recurrence`	RRULE strings for recurring events.
`event_id`	Required for `update` and `delete`.
`calendar_id`	Defaults to `primary`.

manage_focus_time Extended Create, list, update, or delete Focus Time events. 10

Parameter	Description
`action` required	`create`, `list`, `update`, or `delete`.
`start_time`	Start time (required for `create`).
`end_time`	End time (required for `create`).
`summary`	Event title.
`auto_decline_mode`	How conflicting meetings are declined.
`decline_message`	Message sent with auto-declines.
`chat_status`	Chat availability during focus time (e.g., "doNotDisturb").
`recurrence`	RRULE strings for recurring events.
`event_id`	Required for `update` and `delete`.
`calendar_id`	Defaults to `primary`.

Every service in one reference: full API documentation →

OAuth scopes

The server requests only the scopes for the services you enable. In read-only mode it requests just the readonly variants and skips registering write tools entirely.

calendar.readonly list calendars and read events
calendar.events create and modify events
calendar full calendar access (implies both)

Google Calendar MCP questions

Why does the Core tier only have three Calendar tools?: Deliberate design. Every registered tool consumes context window and adds a decision point for the model. Consolidating create/update/delete into manage_event keeps the core schema small without dropping any capability; availability queries and working-status events live in the Extended tier for agents that need them.
Can an assistant check availability before proposing a meeting time?: Yes — query_freebusy returns busy intervals for any set of calendars over a time window, so a scheduling agent can find a genuinely open slot across the whole team instead of guessing from one person’s calendar.
Can it see calendars shared with me, not just my own?: Yes. list_calendars returns every calendar the authenticated account can access, including shared team calendars, and get_events works against any of them by ID.
How do time ranges work for event queries?: get_events takes an explicit time window, so an assistant can ask for "this week", "next Tuesday 9–5", or a whole quarter and only pull the events that matter rather than paging through everything.

Works alongside

All services: Gmail MCP Google Drive MCP Google Calendar MCP Google Docs MCP Google Sheets MCP Google Slides MCP Google Forms MCP Google Tasks MCP Google Contacts MCP Google Chat MCP Google Custom Search MCP Google Apps Script MCP