video.create_preview

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

With no annotations, the description must disclose behavior itself. It states the output type (MP4), the operation (burning subtitles), and the quality/speed tradeoff (fast, downscaled). However, it does not explain side effects such as file creation behavior, default output paths, overwrite semantics, or how configuration files affect the process, leaving meaningful behavioral gaps.

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 a single, well-structured sentence that front-loads the action ('Burn') and contains no filler. Every word contributes to understanding the tool's core purpose.

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 tool with six parameters, two required, and no annotations, the description is too sparse. It does not explain the purpose of config_path, how output paths are determined, overwrite behavior, or preview sizing specifics, leaving the agent with significant missing context despite the presence of an output schema.

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?

The input schema has zero description coverage, so the description must compensate. It only implicitly hints at subtitles_path (ASS subtitles) and preview_width (downscaled), but leaves input_path, output_path, config_path, and overwrite unaddressed, providing minimal parameter-level guidance.

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 uses a specific verb 'Burn' and identifies the exact resource and transformation: ASS subtitles are burned into a downscaled MP4 preview. This clearly distinguishes it from sibling tools like video.render (final output) and video.caption (caption generation) by specifying the preview nature and subtitles input.

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 does not explicitly state when to use this tool versus alternatives like video.render. However, the word 'preview' and adjectives 'fast' and 'downscaled' imply it is intended for quick, low-quality preview rendering, which is an indirectly conveyed usage context.

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