list_mailboxes

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds useful pagination context ('pass nextCursor fields for the next page'), which annotations do not convey. However, it refers to 'nextCursor fields,' a name that appears nowhere in the schema, which muddies rather than clarifies the actual cursor fields.

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?

Two tight sentences with the core action front-loaded and pagination second. No filler, though the second sentence is spent on a field name that does not exist.

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?

No output schema exists, so the description could have described the returned shape and how paging terminates, but it does not. With all three parameters undocumented and an incorrect cursor field reference, an agent lacks what it needs to page correctly.

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 description coverage is 0% and none of the three parameters (limit, lastSort, afterAccountId) are explained: no meaning, ranges, or defaults. The only nod to parameters is 'nextCursor fields,' which does not match any actual parameter name, so it does not compensate for the coverage gap and may actively mislead.

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?

Names a specific verb and resource ('List owned mailbox addresses'), so an agent immediately knows this returns mailbox addresses rather than messages or drafts. It does not explicitly name a sibling or state how it differs from them, but the resource is distinctive enough within the sibling set to be unambiguous.

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?

There is no guidance on when this tool should be chosen, no prerequisites, and no mention of alternatives among the many list_* siblings. The single pagination sentence is procedural, not routing guidance.

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