Create Calendar Event

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

Annotations already indicate idempotentHint and destructiveHint. The description confirms it creates an event but does not disclose authentication needs, potential failures (e.g., invalid mailbox), or side effects. With annotations present, the description adds minimal behavioral context.

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, clear sentence with no redundancy. It is front-loaded and efficient, though perhaps too brief 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?

Given the tool's complexity (18 parameters, nested objects, output schema), the description is extremely sparse. It fails to cover essential context like required parameters beyond the obvious, typical use cases, or behavior of optional fields. The presence of an output schema does not compensate for the lack of explanation of inputs.

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?

Despite 18 parameters and only 33% schema description coverage, the description only explains the relationship between start and timezone. It offers no added meaning for other key parameters like attendees, recurrence, or reminders, leaving the agent to rely solely on sparse 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 and resource: 'Create a calendar event on a mailbox's calendar.' It distinguishes this tool from siblings like shipmail_update_calendar_event and shipmail_delete_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 provides a hint about using start with timezone but lacks explicit guidance on when to use this tool versus alternatives like shipmail_list_calendar_events for reading events. No prerequisites or conditions are mentioned.

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