search_messages_tool

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

No annotations are provided, so the description carries the burden of revealing behavior. It discloses that query/tag are optional and that the result is a list with specific fields, but it does not state matching semantics (e.g., query matched against subject/from/to), case-insensitive exact tag matching, or the slower body-search behavior; these are delegated to schema descriptions.

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?

Three sentences, no filler, with the core purpose first, followed by usage modes and a compact return-value list. Every sentence contributes to selection or invocation.

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 read-only search tool with an output schema and 100% schema coverage, the description covers the essential search modes and result shape. It does not enumerate account/mailbox/body filters, but those are documented in the input schema, so the agent has what it needs to call the tool correctly.

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%, so the baseline is 3. The description adds real semantic value by defining the relationship between query and tag—both optional, with distinct list-by-tag and text-search modes—and by pointing to list_tags for valid tag values. The other parameters (account, mailbox, max_results, include_body) are already well described in the schema.

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 names the exact operation ('Search MailMate messages') and its two key criteria (query string and/or tag), which is enough to distinguish it from sibling tools like open_message_in_mailmate or get_message. It also states the output is a list of matching messages, confirming it is a search/list tool.

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?

It explicitly explains how to combine the optional query and tag parameters ('omit query to list all messages with a given tag, or omit tag to search by text only') and points to list_tags as a prerequisite helper. It does not mention exclusions or when to prefer get_message/open_message, but the main invocation pattern is clear.

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