get-mail-stats

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

No annotations are provided, so the description carries the full burden. It discloses the fast IMAP STATUS optimization and the all-accounts path behavior. However, it does not explicitly state that it is read-only or has no side effects, though this is strongly implied by the purpose.

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 tightly structured with 'Use when', 'Returns', and 'Do not use when' sections. Every sentence earns its place, is concise, and key information is front-loaded.

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 the tool's simplicity (one optional parameter, no annotations) and the presence of an output schema, the description covers the essentials: when to use, what it returns, and when not to use. No critical information is missing.

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 fully describes the account parameter (100% coverage). The description adds value by clarifying the 'all-accounts path' when the parameter is omitted, which is not explicit in the schema and helps the agent correctly choose whether to pass the parameter.

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: aggregate mailbox statistics including total/unread counts, recent activity counts, and per-account breakdown. It uses a specific verb and resource, and distinguishes itself from sibling tools like get-unread-count and list-messages.

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?

Explicit 'Use when' and 'Do not use when' sections provide clear context and explicitly name alternative tools (get-unread-count, list-messages, search-messages). This gives the agent precise decision criteria.

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