gmail_search

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

Annotations already declare readOnly/openWorld/idempotent/non-destructive. The description adds meaningful behavioral details beyond those hints: return format (headers and snippet only), default spam/trash exclusion, max limit of 100, and empty-query behavior. No contradiction with annotations.

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?

Every sentence adds value: intro, operator list, return behavior, follow-up guidance, and a compact Args section. The most important scoping and return information is front-loaded, and no space is wasted on restating titles or obvious types.

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 the output schema exists, the description does not need to explain return types in detail. It covers query syntax, defaults, scope exclusions, limits, and onward routing. An agent has everything needed to select and call this 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 0%, so the description must compensate, and it does thoroughly. Each parameter is explained with a concrete example for query, a maximum bound for limit, and the behavioral effect of include_spam. This far exceeds what the bare schema provides.

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?

States a specific verb ('search') and resource ('mailbox') with Gmail's query syntax. Clearly differentiates itself by noting it returns headers/snippets, not bodies, and points to sibling tools for retrieval. An agent can tell this apart from gmail_get_message and gmail_get_thread immediately.

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?

Describes the query operators and the empty-query fallback, giving concrete context for when to call it. It names follow-up tools for message/thread retrieval, but does not explicitly list exclusions for sibling search/list alternatives. The usage context is clear, though not exhaustive.

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