update_calendar_event

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

With no annotations, the description carries the behavioral burden. It adds value by disclosing the required OAuth scope and the PATCH-like behavior (only provided fields are modified). It does not mention return value, error cases, or side effects like attendee notifications, but the included details go beyond a bare statement of intent.

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 three short sentences, front-loaded with the core action. Every sentence is meaningful; the version prefix 'Official API + UAT' is minor noise but does not hurt clarity.

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 13-parameter update tool with no output schema and no annotations, the description leaves the return value and side effects unspecified. Important operational context such as what happens if the event does not exist, whether attendees are notified, and how recurrence interacts with time changes is absent. The partial-update guidance helps, but this is a minimum viable level of completeness for a complex mutation.

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 coverage is 69%, providing descriptions for most fields. The description adds a crucial semantic: only supplied fields are changed, which directly informs how to use the sparse optional parameters. However, some nested structures (reminders, location) remain under-documented in both schema and 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?

The description begins with 'Patch fields on an existing calendar event,' using a specific verb and resource. It clearly distinguishes from sibling tools like create_calendar_event, delete_calendar_event, and get_calendar_event, and the phrase 'Pass only the fields you want to change' confirms partial-update semantics.

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 tells when to use the tool ('on an existing calendar event') and provides how-to guidance ('pass only fields you want to change'). However, it does not explicitly name alternatives or exclusions, such as not using this for new events or pointing to create_calendar_event instead.

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