List Calendars

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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses key behaviors: listing does not guarantee readability, access requires a probe request, check_access incurs a per-colleague cost, and closed calendars may still expose meeting subjects via get_user_availability. This adds significant non-obvious 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 concise and front-loaded. The first sentence summarizes the core function, and the second paragraph adds important nuance without redundancy. Every sentence contributes value.

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 listing purpose, access semantics, probe cost, and a relevant alternative tool. With an output schema present, return value details are already handled externally. It fully addresses the openWorldHint by mentioning colleagues' calendars and the access uncertainty.

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 input schema already provides a thorough description of check_access, including its cost and effect. The tool description adds motivation for why the parameter exists but no new parameter-level details, so it does not exceed the schema coverage baseline.

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 lists calendars in the sidebar, including whose calendars are accessible. This is a specific verb+resource+scope, distinguishing it from sibling tools like get_calendar_events and get_user_availability.

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 gives practical context: it explains when check_access is needed, notes that a listed calendar may not be readable, and points to get_user_availability as an alternative for meeting subjects on closed calendars. It lacks explicit 'when not to use' but provides clear situational guidance.

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