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

Annotations already establish read-only, idempotent, non-destructive and closed-world behavior, so the bar is lower. The description still adds genuinely new traits: the 45-second bound, the nonterminal-timeout semantics, the nextCall continuation token, and an explicit assurance that no generation, approval, quote, payment or credit state changes.

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 sentences, front-loaded with the action and its time bound, then the response semantics, then the safety statement. Dense but every clause carries information; the credential/approval list in the final sentence is slightly over-enumerated.

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 not be spelled out, yet the description usefully points at video.url for the terminal case. Combined with the timeout/nextCall contract, this covers what an agent needs to call and continue the operation; only sibling comparison is absent.

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 coverage is only 50% (projectId carries no schema description), and the description compensates by explaining that projectId identifies the video and that the optional operationId identifies the original picture/video approval. That adds the missing semantic context, though it does not clarify format or what happens if a stale operationId is supplied.

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 and resource ('Waits ... for active picture generation or the finished video') and adds a concrete bound of 45 seconds, so the agent knows exactly what the call does. It does not name the nearest siblings (studio_generation_status, studio_video_status, studio_motion_wait), so the differentiation is left implicit rather than stated.

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 explains the polling contract ('A pending response is a nonterminal timeout containing the exact nextCall for another bounded wait'), which tells an agent how to loop. However it never says when to choose this over studio_generation_status or studio_video_status, so the selection guidance 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.