mail_search_messages

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 adds context about substring matching in subject and sender, which goes beyond the parameter names. However, it does not disclose behavioral details like case sensitivity, pagination behavior, rate limits, or what happens with no results. The description is adequate but not exhaustive.

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 sentence of 11 words, starting appropriately with the verb 'Search'. It conveys the core purpose without unnecessary fluff. Every word earns its place, making it highly efficient and easy to parse.

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 5 parameters, no output schema, and no annotations, the description is incomplete. It lacks information about return format, pagination, ordering, and other behavioral aspects. The search behavior is partially described, but many necessary details for an agent to correctly invoke and interpret results are 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 description adds meaning to the query parameter by specifying 'by substring in subject or sender', which is not in the parameter names. With 0% schema description coverage, this partial explanation is beneficial. However, other parameters (limit, account, mailbox, unread_only) rely solely on their names for interpretation; no further details are given. The description provides some added value but does not fully compensate for the lack of schema descriptions.

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 verb 'Search' and resource 'messages', specifying the method as substring matching in subject or sender within a mailbox. It effectively distinguishes this tool from other mail tools like 'mail_list_messages' or 'mail_get_message' by the search functionality. However, it does not explicitly differentiate from potential search tools in other domains.

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 no explicit guidance on when to use this tool versus alternatives. It states the search criteria but does not explain when to prefer this over sibling tools like 'mail_list_messages' or how to combine with other operations. No 'when not to use' or alternative tool mentions.

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