update_calendar_event

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states that the update is partial ('Only include fields you want to change') but does not disclose additional behaviors such as whether omitted fields are preserved, permission requirements, idempotency, or error conditions. This is a meaningful gap for a mutation 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 two sentences, front-loaded with the core action, and every word adds value. The second sentence provides crucial usage guidance without padding.

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 tool is relatively simple (6 flat parameters, no nested objects), and the description covers purpose and partial-update semantics. However, it lacks any mention of return values, error scenarios, or permission requirements, which would be expected for a mutation tool. With no output schema, the description leaves some 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?

The schema already describes several parameters (e.g., ISO 8601 for times, HTML for description), but the description adds critical semantics: it clarifies that event_id is the only required field and that all other fields are optional, representing a partial update. This goes beyond the raw schema by explaining the update model, which compensates for the ~33% of parameters without schema descriptions.

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 ('Update') and the resource ('an existing calendar event'), distinguishing it from create/delete siblings. The additional note 'Only include fields you want to change' specifies the partial-update behavior, making the purpose unambiguous.

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 modifying an existing event and warns that only changed fields should be included, which guides the caller on the intended use. It does not explicitly mention alternatives like create/delete, but the sibling names make the distinction obvious, and the context is clear enough.

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