search_threads

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

With no annotations, the description must disclose behavioral traits. It states the tool returns thread ids and snippets in one API call, but does not mention that it is read-only, any authorization needs, rate limits, or pagination behavior. The description adds some context but lacks full transparency.

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?

The description is three sentences, front-loaded with the core purpose, each sentence adding unique value: the search example, return format, and alternative tool. No unnecessary words.

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 search tool with 4 parameters and no output schema, the description explains the search syntax, return type (ids + snippets), and directs to get_thread for full content. However, it omits pagination details (page_token) and does not mention rate limits, which are relevant for API calls.

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 50%, so the description should compensate. It adds the Gmail search syntax example and that an empty query returns latest threads, but does not explain page_token or max_results beyond the schema. The added value is modest.

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 threads using Gmail search syntax, and distinguishes it from get_thread (which retrieves full content). The verb 'search' and resource 'threads' are specific, and the example query clarifies the syntax.

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 a concrete example of when to use this tool and recommends get_thread for full content. However, it does not explicitly exclude alternative tools or mention prerequisites like account connectivity (though implied by parameter).

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