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

Annotations already declare readOnly, idempotent, non-destructive behavior. The description adds useful context beyond annotations: the required demos:read scope, the presence of a generation status field, and the cost/use of includeHtml. It does not describe error behavior, but it substantially enriches the behavioral picture.

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 dense and largely front-loaded with the return shape, then the generation status and includeHtml guidance. It has no filler, though it is a single long paragraph where bullets or slight restructuring could improve scanability.

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, so the description carries the full burden of explaining the return value, and it does so in detail: scene fields, narration status, editable variables, generation progress, and optional HTML. Combined with the permission requirement, this is complete enough for correct invocation.

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%, so the description must compensate for includeHtml, which it does thoroughly by explaining its purpose and when to use it. videoId is already well documented in the schema with an example and pattern. The description meaningfully adds to the parameter semantics.

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 clearly identifies this as retrieving a video and details what the returned video contains (look, voice, music, captions, ordered scenes, generation status). It distinguishes scene-editing siblings by pointing to update_scene and write_scene, but it does not explicitly contrast with get_demo or list_videos.

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 guidance for includeHtml: use it only for hand-editing a scene via update_scene html, and use write_scene to change how a scene looks or moves. It does not state when to choose get_video over get_demo or list_videos, but the main conditional usage is covered.

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