update_calendar_event

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

No annotations are provided, so the description must carry the full burden. It does not disclose side effects, required permissions, error behavior (e.g., event not found), or that it modifies calendar data. It only says 'updates an existing event' without elaboration.

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, concise and front-loaded. However, it is under-specified given the missing parameters and behavioral details.

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?

The description is insufficient for a mutation tool with no output schema and no annotations. It fails to specify which fields can be updated, the input format, or what the response looks like. The missing ID parameter is a critical gap.

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 no properties, yet the description implies an ID parameter ('by ID'). This is misleading and a contradiction. Schema coverage is 100% (empty), so the description adds no value and actually creates confusion.

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 clearly states the verb ('updates'), resource ('existing event in Mac's Calendar app'), and method ('by ID'). It distinguishes from sibling tools like create_calendar_event and delete_calendar_event.

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. It does not mention prerequisites (e.g., needing an event ID from list_calendar_events) or scenarios where other tools like create_calendar_event are more appropriate.

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