mail_search_messages

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

Without annotations, the description discloses two important behaviors (metadata-only search, newest-first ordering) but lacks details like read-only nature, pagination behavior, or what happens with empty results.

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?

Extremely concise: two sentences, front-loaded with key purpose and behavioral constraint. 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?

Despite 18 parameters and no output schema, the description is too sparse. It does not explain the return structure, pagination, or prerequisites. A more complete description is needed for this complexity.

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?

All 18 parameters are fully described in the schema (100% coverage), so the description adds no additional meaning. 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?

Description clearly states it searches local metadata ordered newest-first, and explicitly says it does not read message bodies, which distinguishes it from sibling tools like mail_read_message and mail_read_thread.

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?

Implied usage by stating it does not read bodies, but no explicit guidance about when to use this tool versus alternatives like mail_read_message or mail_list_attachments.

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