gmail_inbox.reply

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

With no annotations, the description alone must disclose behavior. It confirms the tool creates a draft and opens the composer, but does not address permissions, side effects (e.g., whether the draft is saved to the server), or any limitations. It provides basic transparency but lacks depth.

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 that conveys the core functionality without unnecessary words. It is front-loaded and to the point, earning full marks for brevity.

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 complexity of a Gmail reply draft tool with 4 parameters (1 required) and zero schema descriptions, the description is too sparse. It fails to clarify parameter usage, return values, or integration with other tools like gmail_composer.save_draft. The presence of an output schema does not compensate for the lack of parameter guidance.

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 0% description coverage, and the tool description does not explain any parameters (body, subject, user_id, thread_id). The agent must rely solely on parameter names, which is insufficient, especially for ambiguous fields like 'user_id'.

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 action ('create a reply draft') and the resource ('on a thread'), with a note about the composer app opening. However, it does not explicitly distinguish this tool from similar sibling tools like gmail_reply_to_thread.

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 lacks explicit when-to-use, when-not-to-use, or prerequisite information. The note about the composer app implies a workflow but is insufficient.

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