Update Calendar Event

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

With no annotations, the description carries the full burden. It does disclose the partial-update behavior and the required permission (delegated Calendars.ReadWrite), which are valuable. However, it omits potential side effects such as attendee notifications, and does not describe return values or error behavior, leaving gaps for a no-annotation, no-output-schema tool.

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 appropriately sized and front-loaded. The core action ('Update a calendar event') appears first, followed by the patch semantics, permission requirement, and compact Chinese intent list. Each element earns its place without verbosity or repetition.

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 tool with 8 parameters, nested start/end objects, no annotations, and no output schema, the description covers the primary purpose, patch semantics, and permission but leaves out return value details, attendee notification behavior, and potential constraints (e.g., whether start/end must be updated together). The schema handles parameter documentation well, but the overall operational context is incomplete.

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 100%, so the baseline is 3. The description adds meaningful semantics beyond the schema by stating 'Provide only the fields to change', which clarifies that unspecified fields remain untouched—a key intent for PATCH-style operations. This goes beyond the per-field 'New ...' descriptions in the schema.

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 with a specific verb and resource: 'Update a calendar event'. The phrase 'Provide only the fields to change' further distinguishes it from create/delete/cancel operations and clarifies the partial-update semantics. The listed Chinese intents (修改会议, 更新日程, etc.) reinforce the intended use case.

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?

'Provide only the fields to change' implies the tool is for modifying existing events rather than creating or deleting them, and the Chinese intent examples offer clear user-phrase triggers. The mention of 'Requires delegated Calendars.ReadWrite' gives a prerequisite, but it does not explicitly state when not to use this tool or compare it to siblings like calendar_update_calendar.

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