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

Annotations already declare readOnly/non-destructive/closed-world, and the description adds genuinely new behavior: generation takes a few minutes, statuses include pending/running, and the agent should tell the user to come back later. It does not describe failure/error statuses or whether results ever expire, which is the remaining gap.

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?

Three short, front-loaded sentences: what it returns, when to use it, and the async waiting caveat. Tight and useful, with no filler, though the middle and last sentences overlap slightly on the 'check back later' idea.

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?

An output schema exists, so return values need no explanation, and the polling semantics are the main thing an agent needs. The only real omission is the origin of job_id and behavior on a non-success status.

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% for the single job_id parameter, so the description must carry the load. It implicitly frames job_id as identifying a 'CloneMotion video generation job' but never says where the id comes from (presumably the generate call) or what form it takes, so it only partially compensates.

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?

States a specific verb and resource ('Returns status and result of a CloneMotion video generation job') and scopes it to the polling side of video generation, which cleanly separates it from the sibling generate_video_clip. An agent can identify the resource and outcome without opening the 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?

Gives clear use conditions: 'Use when the user wants to check if a generated video is ready or view the generated variants,' plus explicit polling guidance for pending/running states. It does not name the sibling that starts generation (generate_video_clip) or state what to do on a failed status, so the routing is implied rather than exhaustive.

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