Google Calendar MCP Server

Create Event

create_event

Schedule a new Google Calendar event with a title and either start/end times or all-day dates. Add attendees, location, or recurrence rules.

Instructions

Create a new calendar event.

For timed events, provide start_datetime and end_datetime (RFC3339). For all-day events, provide start_date and end_date (yyyy-mm-dd).

Input Schema

TableJSON Schema

Name	Required	Description	Default
`summary`	Yes	Event title
`end_date`	No	End date for all-day events (yyyy-mm-dd, exclusive)
`location`	No	Event location
`timezone`	No	IANA timezone (e.g. 'America/New_York')
`attendees`	No	List of attendee email addresses
`recurrence`	No	RRULE strings (e.g. ['RRULE:FREQ=WEEKLY;COUNT=10'])
`start_date`	No	Start date for all-day events (yyyy-mm-dd)
`calendar_id`	No	Calendar ID (default: 'primary')	primary
`description`	No	Event description
`end_datetime`	No	End time (RFC3339)
`start_datetime`	No	Start time (RFC3339, e.g. '2026-03-15T10:00:00-05:00')

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Sep 13, 2026

TDQS

A3.6/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It conveys the create semantics and the timed/all-day duality, but says nothing about whether attendees are notified, what permissions are required, duplicate handling, or side effects of creating on a shared calendar.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the core action, then the two mutually exclusive parameter modes. Every sentence earns its place with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return values need no explanation, and full schema coverage means parameters are self-documenting. The description covers the main ambiguity (timed vs all-day) but omits any note about recurrence, attendee side effects, or permissions for a mutation tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents every one of the 11 parameters with formats (RFC3339, yyyy-mm-dd). The description restates the same format guidance for the two date modes, adding framing value but no information beyond the structured fields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Create a new calendar event'), so an agent immediately knows the operation. It does not differentiate from siblings like quick_add_event or update_event, but the create-vs-modify distinction is unambiguous from the name and verb.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives conditional usage guidance: timed events need start/end_datetime, all-day events need start/end_date. That is helpful for the parameter mode, but there is no guidance on when to choose this tool over quick_add_event or update_event, so alternative routing is left implicit.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server