calendar_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 behavioral burden. It does not say whether this is a read-only operation, whether shared/subscribed calendars are included, whether results are paginated, or what the response contains — for a tool with zero annotation coverage this is a real gap.

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?

A single front-loaded sentence with no filler, which is appropriate for a simple list operation. It is arguably under-specified rather than padded, so terseness here is a mild virtue rather than a flaw.

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 one-parameter read tool with full schema coverage the description is minimally viable, but with no annotations and no output schema an agent still lacks the safety profile and return-shape context it would want. Adding one clause about read-only semantics and the email requirement would close the gap.

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?

Schema coverage is 100% and the single optional email parameter is well documented in the schema, including the condition for when it is required. The description adds nothing beyond that, which is the expected baseline when the schema does the heavy lifting.

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?

States a specific verb (List) and resource (the user's calendars), so the operation is unambiguous. It does not, however, explicitly distinguish itself from the closely named sibling calendar_list_events, leaving the agent to infer that this returns calendar containers rather than events.

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?

No guidance on when to call this versus calendar_list_events, nor any prerequisite context such as needing a configured account first (setup_list_accounts/setup_add_account exist as siblings). The agent must infer usage entirely from the name.

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