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

The description discloses that the tool returns a WhatsApp link or email instead of directly sending the message, and that the agent must tap to send. It also explains the email fallback behavior, adding value beyond annotations which only indicate a mutation and open world.

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 two sentences with no wasted words. It front-loads the purpose and provides essential details efficiently.

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 low complexity (2 required params, no output schema), the description covers all necessary aspects: how to use, what to pass, and the output format. It is complete for the task.

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 100% schema coverage, baseline is 3. The description adds meaning by specifying that message should be a professional reply and that inquiry_id comes from my_inquiries, enhancing the agent's understanding beyond the schema.

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 replies to a buyer inquiry on a listing, distinguishing it from sibling tools like create_lead and my_inquiries. The verb 'reply' and resource 'inquiry' are specific and unambiguous.

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 clear context for when to use (when replying to a buyer inquiry) and references my_inquiries for obtaining the inquiry_id. It does not explicitly state when not to use or list alternatives, but the guidance is sufficient.

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