List mailboxes

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds value by noting pagination and especially the lag in usage numbers, which is a behavioral nuance an agent must know before interpreting results. This goes beyond the schema and annotations.

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 concise sentences with no filler. The primary action is front-loaded, and the use-case and caveat follow naturally. Every sentence adds value and the length is appropriate for a listing 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 read-only list tool with full parameter documentation and safety annotations, the description covers the purpose, the returned data aspects, and a key caveat (lagging usage). It does not detail pagination mechanics, but these are evident from the parameters. It is complete enough for an agent to call 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?

All five parameters have schema descriptions with 100% coverage, so the schema carries the parameter semantics. The description does not add extra detail about how to combine or use parameters beyond what the schema states; it only mentions pagination generically. Baseline of 3 is appropriate given full schema coverage.

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 it retrieves a paginated list of mailboxes for a mail order, with a specific verb, resource, and scope. It also enumerates the data it returns (status, protocols, resource counts, usage), which distinguishes it from sibling list tools like mail_listForwardersV1 or mail_listAliasesV1 without ambiguity.

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 explains the intended use case: monitoring mailboxes and their attributes, including a caveat about lagging usage numbers. It does not explicitly name alternatives or state when NOT to use this tool, but the context clearly implies this is the mailbox-specific list, so an agent can infer the right choice from the sibling names.

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