video_preview

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

With no annotations provided, the description carries full burden but provides minimal behavioral information. It mentions 'fast' processing but doesn't disclose performance characteristics, file format support, error conditions, or whether it modifies the original video. This leaves significant gaps for a tool that creates new files.

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 perfectly structured with a clear purpose statement followed by parameter explanations. Every sentence earns its place, and the information is front-loaded with the core functionality stated first. No wasted words or redundancy.

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?

Given 3 parameters with no schema descriptions, the description does well explaining parameters. However, with no annotations and a tool that creates output files, it should provide more behavioral context about performance, file handling, and error conditions. The existence of an output schema helps but doesn't fully compensate for missing operational details.

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?

With 0% schema description coverage, the description compensates well by explaining all three parameters in the Args section. It clarifies that output_path is optional with auto-generation, defines scale_factor meaning (4 = 1/4 resolution), and specifies input_path requirements. Only minor details like path format expectations are missing.

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 states the specific action ('Generate a fast low-resolution preview') and resource ('input video'), distinguishing it from siblings like video_thumbnail (single image) or video_storyboard (multiple frames). It precisely communicates the tool's purpose beyond just the name.

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 provides clear context ('for quick review'), which helps differentiate from more detailed video processing tools. However, it doesn't explicitly mention when NOT to use it or name specific alternatives among the many sibling tools, preventing a perfect score.

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