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

With only idempotentHint=true in annotations, the description carries the full behavioral burden and does so thoroughly: it discloses the return shape and status values, extra progress fields for epub-audiobook, polling interval, failure behavior (error message, no automatic retry), and cost ('free, no payment'). Nothing here contradicts the annotation.

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 front-loaded with purpose and usage, then adds return format, polling guidance, and exclusions. It is highly informative but somewhat long, with several sentences that could be combined without losing meaning, so it is structured well but not maximally tight.

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 no output schema and minimal annotations, the description is complete enough for correct invocation: it explains the return values, status transitions, progress field for one job type, polling cadence, failure handling, and the follow-up tool to call. Nothing critical is missing.

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%, so both parameters are already documented in the input schema, including the enum mappings and fallback jobTypes. The description reinforces that requestId comes from async tools but does not add syntax, format, or constraints beyond what the schema provides, so 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 opens with a specific verb and resource: 'Poll the status of an async job.' It explicitly names the sibling tools it follows (generate_video, animate_image, etc.) and distinguishes itself from get_job_result and synchronous tools, so an agent can tell what it does and where it fits without opening another schema.

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?

It gives explicit when-to-use rules ('after calling any async tool that returns a requestId'), polling cadence ('every 5-10 seconds'), next-step routing ('call get_job_result' on COMPLETED, do not retry on FAILED), and a clear when-not-to-use warning ('Do NOT use for synchronous tools'). The alternatives and conditions are fully spelled out.

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