list_calendars

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

No annotations are provided, so the description carries the full burden. The verb 'List' naturally conveys a non-destructive, read-only operation, which is a form of behavioral disclosure. However, the description does not mention what exactly is returned (e.g., calendar IDs, names, metadata) or any other behavioral traits like sorting or filtering.

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 wasted words. Every word earns its place, and the structure is optimal for a simple list operation.

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?

For a zero-parameter list operation with no output schema, the description provides a sufficient understanding of the tool's basic purpose. It does not specify the return format or potential errors, but given the low complexity, this is not a critical gap. A richer description could mention that it returns calendar IDs for use in other operations, but the current description is adequate.

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 tool has zero parameters, and the schema confirms this with 100% coverage. According to the rubric, the baseline is 4 for zero-parameter tools, and the description does not need to add parameter semantics. No further elaboration is required.

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?

Description clearly states the action ('List') and the target resource ('calendars'), distinguishing it from list_events and other siblings. The verb-resource pairing is specific and unambiguous for a read-only inventory operation.

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 context (retrieving available calendars), but does not explicitly state when this tool should be preferred over alternatives or mention any prerequisites or exclusions. Given the tool's simplicity, the implied context is sufficient but not fully explicit.

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