List Gmail Threads

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is well-covered. The description adds the return structure (threads with message count and snippet) and parameter details, but no additional behavioral traits such as pagination behavior, rate limits, or authentication requirements beyond what the annotations imply.

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 with an initial purpose statement, an Args section, and a Returns section. It is concise and front-loaded, though the Args section largely duplicates the schema. It avoids unnecessary verbosity while remaining complete.

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 moderate complexity (5 parameters, no output schema), the description adequately covers the input parameters, defaults, and return format. It lacks usage-guidance context (e.g., when to choose this over gmail_list_messages), but this is already scored under usage_guidelines. The description is otherwise complete for a straightforward list operation.

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?

Input schema covers all 5 parameters with descriptions and defaults, giving 100% coverage. The description repeats these parameter names and descriptions, but adds little semantic value beyond the schema, so the baseline of 3 is appropriate.

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 states a specific verb ('List') and a specific resource ('conversation threads from Gmail'). This clearly distinguishes it from sibling tools like gmail_list_messages, which lists individual messages rather than 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?

No guidance is provided on when to use this tool versus alternatives. The description lists parameters and return values but does not mention situations where gmail_list_messages or gmail_get_thread would be more appropriate, nor does it suggest any prerequisites or exclusions.

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