video_storyboard

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions that frames are saved to an output directory and that output_dir is auto-generated if omitted, which adds some context. However, it lacks critical behavioral details such as whether the tool modifies the original video, what permissions are needed, how key frames are selected (e.g., evenly spaced, based on scene changes), or any rate limits. For a tool with 3 parameters and no annotations, this is a significant gap.

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 efficiently structured with a clear purpose statement followed by a bullet-point list of parameters. Every sentence earns its place: the first sentence defines the tool's function, and the parameter explanations are necessary given the 0% schema coverage. There is no redundant or verbose language.

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 the tool's moderate complexity (3 parameters, no annotations, but has an output schema), the description is partially complete. It covers the basic purpose and parameters adequately, but lacks usage guidelines and detailed behavioral context. The presence of an output schema means the description doesn't need to explain return values, which helps, but the gaps in behavioral transparency and usage guidance prevent a higher score.

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 description coverage is 0%, so the description must compensate. It provides meaningful semantics for all three parameters: input_path is explained as 'Absolute path to the input video,' output_dir as 'Directory to save frames' with auto-generation behavior, and frame_count as 'Number of key frames to extract.' This adds substantial value beyond the bare schema, though it doesn't specify constraints like valid frame_count ranges or output_dir path requirements.

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 tool's purpose with specific verbs ('Extract key frames' and 'create a storyboard grid') and identifies the resource ('input video'). It distinguishes itself from sibling tools like video_thumbnail (single frame) or video_preview (preview generation) by focusing on multi-frame extraction for storyboard creation.

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 no guidance on when to use this tool versus alternatives. It doesn't mention when this tool is appropriate (e.g., for planning edits, content review) or when other tools like video_thumbnail or video_preview might be better suited. The only implicit usage hint is 'for human review,' but this is insufficient for distinguishing from sibling tools.

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