calendar_update_event

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 only states 'Update' without detailing behavioral aspects such as whether it performs a partial update (only specified fields are changed) or a full replacement. There is no mention of authorization requirements, idempotency, or side effects.

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?

The description is a single sentence, which is concise but lacks important details that could be included without much length. It is front-loaded with the purpose, but every word earns its keep. However, it is too minimal to be highly effective.

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?

Given 10 parameters and no output schema or annotations, the description is insufficient. It does not explain the behavior of the update (e.g., whether start and end times must be provided together, or how attendees are replaced). The agent may need to infer from the schema, which is risky.

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?

The input schema has 100% description coverage, so the baseline is 3. The description does not add any additional meaning beyond the schema's parameter descriptions. The schema itself is clear, but the tool description offers no extra value.

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?

The description 'Update an existing calendar event' clearly states the action (update) and the resource (calendar event), which distinguishes it from siblings like calendar_create_event and calendar_delete_event. However, it could be more specific by mentioning which fields can be updated.

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 provides no guidance on when to use this tool versus alternatives (e.g., calendar_quick_add for quick additions). It does not specify that the eventId must be obtained from calendar_list_events first, nor does it mention any prerequisites like needing write access to the calendar.

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