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

Annotations only say readOnlyHint=true; the description adds what the annotations can't: the polling cadence, expected wall-clock durations per model (Kling 3.0 ~2 min, Seedance 2-4, Omni/Motion Control/Veo 3-6), that the call is free, and exactly which result fields appear on completion (video_url + poster_url, image_url, file_url). That is real behavioral context beyond structured data.

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?

Front-loaded with the core action and polling guidance, then return values, then model timings. It is dense with no filler, but the telegraphic fragments ('Seedance 2-4', 'Free.') cost a little readability.

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?

There is no output schema, and the description compensates by enumerating the completion payload fields. With polling cadence, per-model latency, and the free-cost note, an agent has everything needed to call and interpret this 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 0%, so the description must carry the parameter burden and it largely does: frames is defined with its valid range (4-24), its meaning (a finished clip's contact sheet) and its cost (free). task_id is only implied by 'by id' without a format hint, which is the one small gap.

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?

Opens with a specific verb+resource: 'Status of a task by id', which is precisely what the tool does and is distinguishable from list_tasks by the 'by id' framing. It stops short of naming the sibling that lists tasks, so it isn't maximally differentiated.

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?

Gives concrete operational guidance: poll long jobs every ~15-30s, and per-model expected durations so the agent knows how long to wait. It never states when to use this versus list_tasks or cancel_task/retry_task, so the alternative routing is implied rather than explicit.

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