gmail_threads_list

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

Annotations already declare readOnlyHint=true, so the description adds no further behavioral details. The description does not mention pagination, limits, or that results may be thread summaries. However, it does not contradict annotations, so a baseline of 3 is appropriate.

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 a single concise sentence with no waste. While very terse, it effectively communicates the core action. It could be slightly expanded for clarity but remains well-structured.

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 is a simple list operation with fully documented parameters and no output schema, the description is minimally adequate. It lacks details like pagination behavior, query syntax notes, or what thread fields are returned, but it is not grossly incomplete.

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 input schema has 100% coverage, fully describing all three parameters (q, userId, maxResults). The description only indirectly references 'q' via 'matching a query', adding no additional semantic value beyond what the schema already 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?

The description clearly states the verb 'List' and the resource 'Gmail threads', and specifies the filtering aspect 'matching a query'. This effectively distinguishes it from sibling tools like gmail_threads_get (single thread retrieval) and gmail_messages_list (messages vs threads).

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 such as gmail_threads_get or gmail_messages_list. It lacks any context about prerequisites, query syntax hints, or recommended use cases.

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