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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states the return fields (status, chapters_done, total_chapters) and the conditional nature of download_url (only when complete), which gives the agent insight into expected behavior. It stops short of describing error cases or eventual statuses like failure, but for a status-check tool it provides adequate transparency.

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 concise sentences. The first sentence states the action and target, and the second lists the return values and their condition. There is no wasted wording or redundancy, making it efficient and easy to parse.

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 lack of an output schema and annotations, the description does well by explicitly listing return fields and the condition for download_url. However, it does not mention possible job statuses (e.g., failed, pending) or how to handle errors, which could be inferred from the sibling retry_job tool. For a simple polling tool, this is nearly complete but leaves a small gap around failure handling.

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 already provides 100% coverage for the single parameter job_id with a clear description ('The job ID returned by generate_ebook'). The tool description does not add any additional meaning or constraints about the parameter, so it does not exceed the baseline set by schema coverage.

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 action ('Check the status and progress') on a clear resource ('an eBook generation job'). It distinguishes this tool from siblings like generate_ebook, retry_job, and download_epub_url by focusing on status retrieval. The purpose is unambiguous and directly actionable.

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 implies usage after job creation (via 'download_url when complete' and the schema's reference to generate_ebook), but it does not explicitly state when to use this tool versus alternatives like retry_job. No exclusions or alternative conditions are provided, so the guidance is limited to an implied workflow rather than explicit recommendations.

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