mail_search

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

Annotations already declare readOnlyHint=true, so the description doesn't need to reiterate safety. It adds that it returns IDs and nextPageToken, which is beyond schema. It also notes SMTP limitation, which is useful. However, it doesn't disclose pagination behavior beyond nextPageToken, or query syntax details. With annotations covering safety, this is adequate.

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?

Two sentences, efficient, front-loaded with the primary function and return value. The SMTP note is a bit tangential but adds value. No waste.

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?

Output schema exists, so return values are covered. But with 0% parameter coverage and no guidance on query syntax or pagination usage, an agent may struggle to construct correct queries. Annotations cover safety. Missing parameter semantics is the main gap.

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 description coverage is 0%, meaning the description must compensate. The description mentions query syntax but does not explain the parameters: limit, query, account_id, page_token. It doesn't add meaning beyond what the schema provides (names and defaults). Since coverage is 0%, this is a significant gap; the description should explain expected formats for query and page_token.

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 searches Gmail messages using Gmail query syntax and returns IDs and nextPageToken. It distinguishes from siblings by mentioning SMTP cannot read, which sets it apart from mail_read and other mail tools. Specific verb 'Search' + resource 'Gmail 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?

The description implies this is for searching, not reading or sending. It explicitly notes SMTP cannot read, which indirectly routes to mail_read for reading. However, it doesn't explicitly say when to use this vs mail_read or mail_thread, so usage context is clear but exclusions are minimal.

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