mailbox_stats

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

With no annotations, the description carries full burden, but it does not disclose whether the tool is read-only, whether it modifies mailbox state, or what side effects might occur. 'Aggregate' suggests computation but does not explicitly state safety or return behavior.

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 a single, front-loaded sentence that conveys purpose and scope without unnecessary words. It is appropriately sized for a simple tool with no parameters.

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?

Given no annotations and no output schema, the description should explain what the tool returns and any limitations, but it only lists a few stat types without describing the output format or scope (e.g., all mailboxes vs. filtered). This is insufficient for complete understanding.

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 zero parameters, so schema coverage is 100% and there is no need for parameter explanations. The description adds context about the kinds of stats returned (counts, priorities, live agents), which is helpful but not required for parameters.

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 ('aggregate') and resource ('mailbox stats') and further specifies the stats included (counts, priorities, live agents). This clearly distinguishes it from sibling tools like list_chats or mark_unread, which are action- or list-oriented.

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 when aggregate mailbox statistics are needed, but it does not explicitly state when to use this tool over alternatives such as list_chats or mailbox_board. There is no mention of exclusions or when not to use it, so guidance is only implied.

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