Send a calendar invitation to attendees with a title, start and end times, and optional location. Times without an offset use the specified or mailbox time zone.
Send a calendar invitation. Times without offset use the given or mailbox time zone.
| Name | Required | Description | Default |
|---|---|---|---|
| end | Yes | ||
| start | Yes | ||
| title | Yes | ||
| location | No | ||
| timezone | No | IANA zone for times without offset; defaults to the mailbox timezone | |
| attendees | Yes | ||
| description_markdown | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden. It usefully discloses one real behavioral rule (offset-less times resolve to the given or mailbox time zone), but omits whether invitations are emailed to attendees, permission requirements, or idempotency behavior for a write tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two tight sentences with the purpose front-loaded and the timezone caveat second; nothing is wasted. It is efficient but very sparse given the tool's complexity.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a 7-parameter write operation with no annotations and no output schema, the description is thin: it does not explain notification behavior, required attendees, failure modes, or the shape of the created event, leaving the agent under-equipped.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is only 14% (only timezone is documented), so the description must compensate and largely does not. It clarifies time/timezone handling but says nothing about attendees, title, location, or description_markdown semantics beyond what the schema names imply.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
"Send a calendar invitation" gives a clear verb (create/send) and resource (calendar event), and the name aligns with it. It is distinguishable from update_event and cancel_event by its creation framing, though the description never explicitly contrasts with those siblings.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no guidance on when to use this versus update_event, cancel_event, or send_message, nor any stated preconditions. The agent must infer everything from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.