Update calendar event

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

Beyond annotations (readOnlyHint=false, destructiveHint=false), the description only adds 'Replace' to indicate mutation. It does not disclose whether changes are reversible, require specific permissions, or affect other attendees. The term 'replace' suggests full overwrite, but this is not explicitly stated.

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, front-loaded sentence that efficiently conveys the core purpose. However, it omits important details that could be added without significant length increase, such as usage context or parameter hints.

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 11 parameters, no output schema, and no explanation of update semantics (full replacement vs partial), the description is insufficient. Key details like date-time formats, required fields, and return value are missing, leaving large gaps for the agent.

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?

With only 18% schema description coverage, the description adds minimal parameter insight. Only objectUrl is mentioned ('from calendar_list_events'). No explanation for required fields like start, end, summary, or their formats. The description does not compensate for the low schema coverage.

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 action 'Replace an existing calendar event by its object URL.' The verb 'replace' distinguishes it from siblings like calendar_create_event (create) and calendar_delete_event (delete). The method 'by its object URL' specifies a unique input requirement.

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 implies usage for updating existing events when you have the object URL, but it does not explicitly state when to use this tool vs alternatives like calendar_create_event or calendar_tentative_event. No guidance on prerequisites or exclusions is provided.

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