List Mailboxes

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

With no annotations, the description carries the behavioral burden. The word 'List' and the qualifier 'configured' convey a read-only, scoped enumeration, but the description does not disclose edge-case behavior such as invalid account names or whether synced data is required.

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. Every word contributes meaning, and the scope qualifiers are efficient.

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 simple tool with one documented parameter and an output schema, the description is sufficiently complete. It could mention that account names come from list_accounts, but this is optional rather than essential.

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 schema already documents account_name fully, including an example. The description adds only 'for an account,' which does not meaningfully extend the parameter semantics.

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 states a specific action ('List') and resource ('configured mailboxes and folders') scoped to 'an account'. This clearly distinguishes it from sibling tools like list_accounts and search_emails.

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: it is the enumeration step for a given account, but it does not explicitly say when to use this tool versus alternatives, nor does it mention prerequisites such as listing accounts first.

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