search_emails

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is partly covered. The description adds genuinely useful context that annotations cannot express: results come from third parties and are wrapped in an UNTRUSTED block whose instructions must be ignored. It says nothing about pagination or how many results come back per call, which is a minor gap.

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 dense sentences with zero filler. The capability is stated first and the safety advisory follows immediately, which is the correct order for an agent that must decide whether to call before it reads results.

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 full schema coverage and no output schema, the description covers what an agent needs to call it correctly and to treat results safely. The missing piece is routing versus search_all_accounts, which matters given that sibling exists.

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 would be 3, but the description earns extra credit by giving concrete Gmail operators (from:, subject:, newer_than:) that add real meaning beyond the schema's bare "Gmail search query". The account and max_results parameters are left entirely to 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?

"Searches mail using Gmail syntax" pairs a specific verb with a specific resource and even names the query dialect, so an agent immediately knows what the tool does. It stops short of distinguishing itself from the sibling search_all_accounts, so the scope (single account vs. all accounts) must be inferred from the required account parameter.

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?

There is no explicit when-to-use or when-not-to-use guidance, and the obvious alternative, search_all_accounts, is never named. The only implicit signal is the required account parameter, which suggests a single-account scope but is not stated.

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