search_gmail_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 describes what the tool returns (Message IDs, Thread IDs, web links) and mentions the default page_size, which is useful. However, it doesn't disclose important behavioral traits like whether this is a read-only operation, authentication requirements, rate limits, pagination behavior beyond page_size, or error handling. The description adds some value but leaves significant gaps.

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 well-structured and appropriately sized. It uses clear sections (Args, Returns) with bullet-like formatting that makes parameter information easy to parse. Every sentence adds value: the first states the purpose, the second describes the return format, and the parameter descriptions provide essential details. No wasted words or redundancy.

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 tool's moderate complexity (4 parameters, no annotations, no output schema), the description is partially complete. It covers the basic purpose and most parameters well, but has significant gaps: missing documentation for the 'service' parameter, no behavioral context beyond basic returns, and no guidance on when to use versus alternatives. For a search tool with authentication requirements, this leaves important questions unanswered.

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?

With 0% schema description coverage, the description must compensate for the lack of parameter documentation in the schema. It successfully documents 3 out of 4 parameters (query, user_google_email, page_size) with clear semantics, including the default value for page_size and that user_google_email is required. However, it completely omits the 'service' parameter, which is required according to the schema, creating a significant documentation gap.

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 messages in Gmail based on a query, which is a specific verb+resource combination. However, it doesn't distinguish this tool from the sibling 'search_messages' tool, which appears to be a similar functionality. The description mentions returning both Message IDs and Thread IDs with web links, which adds specificity but not sibling differentiation.

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 no guidance on when to use this tool versus alternatives. There's no mention of when this tool should be used instead of sibling tools like 'search_messages' or 'get_gmail_message_content', nor any prerequisites or exclusions. The only contextual information is that it searches 'in a user's Gmail account,' which is implied by the tool name.

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