preview_video_task

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

With readOnlyHint/destructiveHint/openWorldHint already declaring the safety profile, the description still adds substantial behavioral context: playback only on user click, reads saved results only, and an explicit negative list (no backend polling, media download, generation, spending or configuration changes). This tells the agent exactly what side effects will not occur.

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 purpose, then behavior, then the host-support caveat. Dense and mostly free of filler, though the enumeration of player features (seek, volume, fullscreen, retry) is borderline detail an agent does not need for tool selection.

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?

For a single-param read-only preview tool with no output schema and full annotation coverage, the description covers purpose, trigger, and non-effects adequately. It does not describe what happens if the task has no completed video yet or the handle is invalid, which is the main remaining gap.

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?

Only one parameter (task_handle) with 0% schema description coverage, so the description should compensate. It hints that the handle refers to an 'owned locally saved task', implying ownership and locality constraints, but adds no format, lookup or failure semantics beyond the schema's UUID pattern.

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+resource: 'Show generated videos ... in an inline player', so the agent immediately knows this renders existing video output rather than fetching or generating it. It does not explicitly differentiate itself from siblings like get_generation_task or preview_audio_task/preview_image_task, which is the only thing keeping it out of the top band.

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 a clear trigger condition ('Call once when completed video becomes available') and a deployment caveat ('Always also include named original video links for hosts without UI support'). It does not name the alternative to use when the video is not yet complete, so usage is implied rather than fully routed.

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