get_mailbox_info

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

No annotations are provided, so the description carries the full disclosure burden. It implies a read by describing returned data but says nothing about permissions required, whether the mailbox identity can change, or how the allowlist is represented. For a zero-parameter identity tool the burden is light, but the gap is still real.

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 sentence with no padding, appropriately sized for a trivial zero-param tool. The phrasing 'who you may receive mail from and send mail to' is slightly awkward but still parses quickly.

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?

With no output schema, the description must convey what comes back, and it does at a high level: the mailbox address and the permitted sender/recipient set. It omits format details (e.g., whether allowlists are addresses, domains, or patterns), but for a no-argument info tool this is close to sufficient.

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 takes no parameters (0 required, empty properties), so there is nothing to document and the baseline of 4 applies. The description correctly adds no parameter detail, as there are none.

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 names the resource content (mailbox address plus inbound/outbound allowlists), which distinguishes it from the list_*/send_* siblings. However, it is a noun phrase with no action verb, so it never explicitly states that the tool retrieves this information rather than configuring it.

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 when-to-use guidance, no prerequisites, and no mention of alternatives among the ten sibling tools. The agent must infer that this is the identity/permissions lookup step before send_message or read_message.

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