List named Gmail mailboxes

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

The description adds minimal behavioral context beyond the annotations. The readOnlyHint, openWorldHint, and idempotentHint already convey that this is a safe, read-only listing operation. The phrase 'connected' adds a small amount of scope information, but no deeper behavior is disclosed.

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 two short, focused sentences. It front-loads the operation and immediately follows with a practical use case. Every sentence earns its place with no redundancy.

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, read-only, idempotent listing tool, the description is complete. An agent knows what the tool does, when to invoke it, and has no additional parameters or prerequisites to worry about.

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 params, so schema coverage is effectively 100% and there is nothing for the description to compensate for. The baseline of 4 applies because there are no parameter semantics to clarify.

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 uses a specific verb and resource: 'List connected Gmail mailbox aliases.' It clearly identifies the operation as listing available aliases, which distinguishes it from sibling tools like read_email, connect_mailbox, or search_mailboxes.

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 explicitly states when to use this tool: 'when an alias is unknown or the user asks which mailboxes are available.' This gives clear context, though it does not name alternative tools or explicitly state when not to use it.

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