Modify a calendar event you created and notify attendees with an updated invitation. Adjust title, time, location, or details while keeping everyone informed.
Change an event you created; attendees get an updated invitation.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | ||
| end | No | ||
| start | No | ||
| title | No | ||
| location | No | ||
| timezone | No | IANA zone for times without offset; defaults to the mailbox timezone | |
| attendees | No | ||
| description_markdown | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does disclose one important behavioral trait: attendees receive an updated invitation, which is exactly the side-effect an agent needs to know before mutating a shared event. However, it omits whether updates are partial or full-replace, whether clearing fields is possible, permission requirements, and whether notifications can be suppressed.
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?
One compact sentence, front-loaded with the verb and resource, with the side effect as a subordinate clause. Nothing wasted.
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?
No annotations, no output schema, and 8 parameters with only 13% schema coverage. The description should compensate for this sparse structured data but does not — it says nothing about partial updates, required ownership/auth, notification behavior, or timezone semantics beyond the schema's own field description.
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 13% (only the timezone field has a description). Eight parameters, including start/end with strict patterns and attendees with an email format, are undocumented in the description. The description adds zero parameter guidance beyond the general message, leaving half the surface area unexplained in both schema and prose.
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?
Clear verb+resource ('Change an event') with an explicit ownership scope ('you created') that differentiates it from siblings like create_event and cancel_event. The second clause ('attendees get an updated invitation') specifies the side effect, which no sibling shares.
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?
The ownership constraint ('you created') implies when this tool applies versus cancel_event or create_event, but no alternatives are named and no prerequisites are stated. Adequate for a mid-range social-calendar tool, but guidance is inferential rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.