gws.mail.read_thread

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds the scope ('all messages') but doesn't mention return format, ordering, or potential large response sizes. With annotations providing the core behavioral context, this modest addition is adequate.

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 filler or repetition. It fully communicates the tool's purpose without exceeding necessity.

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 simple read operation, the description covers the essential purpose. There is no output schema, but the description implies a collection of messages. Combined with the schema's format parameter, the context is sufficiently complete for an agent to select and invoke the tool correctly.

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 100%, with each parameter (format, account, threadId) already well-documented. The tool description doesn't add additional parameter semantics, so the baseline 3 applies.

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 is specific and unambiguous: 'Read all messages in an email thread' clearly identifies the verb (read), resource (email thread), and scope (all messages). This distinguishes it from sibling tools like gws.mail.read_message (single message) and gws.mail.search.

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 clearly conveys when to use this tool: when the entire thread content is needed. While it doesn't explicitly name alternatives or exclusions, the 'all messages' wording provides clear context that differentiates it from single-message reads.

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