update_event

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

Annotations already declare this as a non-read-only, non-destructive, idempotent operation. The description adds key behavioral context by stating 'only provided fields change', which clarifies partial-update semantics and that omitted fields are left untouched. This goes beyond the annotation information, though it does not address edge cases like null values or error behavior.

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 conveys the core action and scope without any redundancy or filler. It is appropriately sized for the tool's complexity.

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 covers the primary update behavior but omits the return value or response format, which is important since there is no output schema. It also does not mention error scenarios or prerequisites like the event existing. While the annotations and schema cover some context, the lack of return-value disclosure leaves a gap for a mutation tool.

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 0% schema description coverage, the description must compensate for the meaning of the six parameters. It only provides a general rule for 'provided fields' but does not explain formats (e.g., date/time for start/end), the semantics of null, or the role of time_zone. Parameter titles are self-explanatory but insufficient for precise invocation.

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 tool's action ('Update fields') and resource ('existing event'), with the parenthetical 'only provided fields change' adding precise scope. This distinguishes it from sibling tools like create_event and delete_event, which have different verbs and resources.

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 phrase 'existing event' implies this is for modifying already-created events, not for creating new ones (which would use create_event). However, it does not explicitly mention alternatives or conditions when not to use it, leaving usage largely implied rather than explicitly guided.

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