Update an existing calendar event by ID, changing only the fields you specify, such as title, time, location, or description.
Update an event. Only set the fields to change.
| Name | Required | Description | Default |
|---|---|---|---|
| endAt | No | Datetime as YYYY-MM-DD HH:MM:SS | |
| title | No | ||
| eventId | Yes | ||
| startAt | No | Datetime as YYYY-MM-DD HH:MM:SS | |
| isAllDay | No | ||
| location | No | ||
| timezone | No | ||
| description | 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 discloses partial-update semantics ('Only set the fields to change'), which is genuinely useful, but omits permissions/auth needs, whether omitted fields are preserved vs cleared, concurrency behavior, and any reversibility notes for a mutation.
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 short sentences, front-loaded with the verb and immediately followed by the most important behavioral caveat. No wasted words, though it is arguably too terse for an 8-parameter mutation tool.
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 mutation tool with no annotations, no output schema, 8 parameters at 25% coverage, and no sibling differentiation, the description is materially under-specified. It should cover partial-update behavior in more depth, required identifiers, and any side effects.
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 25% (just the two datetime fields), leaving six parameters undocumented in both schema and description. The description's 'only set fields to change' adds partial-update intent but does not explain semantics of title, location, timezone, isAllDay, or description.
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?
States a specific verb+resource ('Update an event') that clearly identifies a mutation on a calendar event, distinguishing it from read siblings like calendar_list_events. However, it offers no differentiation from calendar_create_event or calendar_delete_event beyond the verb.
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 description gives no when-to-use context and names no alternatives. It does not clarify when to use update vs create, nor whether the event must already exist. The only guidance is the partial-update hint 'Only set the fields to change.'
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.