update_calendar_event

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

The description adds the behavior 'Only provided fields are changed', which is not in the annotations. However, annotations already include destructiveHint: true, and the description does not elaborate on side effects or error handling.

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 consists of two concise sentences without any wasted words. It is front-loaded with the action and resource.

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 adequately explains the core behavior for a simple update tool, but lacks information about return values or possible errors. Given no output schema, this is a gap, but not severe for a straightforward 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?

All parameters have descriptions in the schema (100% coverage). The description adds minimal extra meaning beyond the schema, stating that only provided fields are changed, which is already inferable from the required field list.

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 verb 'Update' and the resource 'existing calendar event', and adds the key behavioral detail 'Only provided fields are changed'. This distinguishes it from sibling tools like 'create_calendar_event'.

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 does not provide explicit guidance on when to use this tool versus alternatives, such as not to use it for creating new events. The context is implied but not stated.

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