search_messages

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the read-only search nature, the accepted Gmail search syntax, and the exact return shape (subject/from/date/snippet). It omits authentication or rate-limit details, but core behavior is well communicated.

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?

One concise sentence with an illustrative example and explicit return fields. The core purpose is front-loaded ('Search Gmail'), and every clause provides useful information without filler.

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 two simple parameters and no output schema, the description sufficiently covers query semantics, result format, and invocation basics. A note about ordering or pagination would be a minor enhancement, but it is not essential for correct use.

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?

The description adds important meaning to the query parameter by giving a concrete Gmail search syntax example, which is crucial since schema description coverage is 0%. The max_results parameter is not described in text, but its name, default, and maximum are self-explanatory in the input 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?

The description clearly identifies the action (search), the target resource (Gmail messages), and the distinguishing feature of Gmail search syntax. It also states the return type as a list of messages with specific fields, making it distinct from siblings like get_message and list_labels.

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 provides clear context for when to use the tool: searching Gmail with Gmail's query syntax. However, it does not explicitly say when not to use it or recommend alternatives, such as using get_message for a specific message or list_labels for label operations.

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