get_mailbox_stats

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions 'compact' stats, which hints at the output nature, but doesn't discuss whether the operation is read-only, potential rate limits, permission requirements, or error conditions. The description is too brief to adequately inform an AI agent about behavioral expectations.

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 sentences that get directly to the point. It front-loads the action and includes only essential information, with no wasted words.

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 optional parameter and examples of return values, the description is largely complete. The schema handles the parameter details, and the description clarifies the tool's purpose. It could be improved by explicitly stating the behavior when mailboxId is omitted, but that is already in the schema.

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 coverage is 100% for the only parameter, mailboxId, which already includes its description and optionality. The tool description does not add any additional meaning beyond the schema, so the baseline score of 3 is appropriate.

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 the tool's function: retrieving compact mailbox statistics such as email counts, unread counts, and thread counts. It also distinguishes the tool from listing mailbox contents, which helps differentiate it from sibling tools like get_mailbox_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 provides an explicit use case: 'when you need an overview instead of listing mailbox contents.' This implies the alternative of listing contents, but it doesn't name specific sibling tools or state when not to use this tool. The guidance is clear for common scenarios, but lacks explicit alternative naming.

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