video_extract_frame

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

With no annotations provided, the description carries the burden of disclosing behavioral traits. It states the tool extracts a single frame, implying non-destructive behavior, but does not mention requirements (e.g., file permissions, supported formats) or potential side effects.

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 extremely concise, using a single line for the purpose and a bulleted list for parameters. Every sentence adds value with no redundancy or fluff.

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 simple nature of the tool and the presence of an output schema, the description covers the essential aspects. It could include a note on output format or resolution, but the current information is sufficient for a basic extraction task.

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?

Despite 0% schema description coverage, the description adds significant meaning to each parameter: input_path as 'Absolute path to the video', timestamp as 'Time in seconds to extract', and output_path as 'Where to save the frame. Auto-generated if omitted.' This compensates fully for the schema's lack of descriptions.

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 'Extract a single frame from a video for visual verification' clearly states the action (extract), the resource (a single frame from a video), and the purpose (visual verification). This distinguishes it from sibling tools like video_export_frames which export multiple frames.

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 provide explicit guidance on when to use this tool versus alternatives. While it mentions 'visual verification,' it lacks comparisons to similar tools like video_export_frames or video_analyze, leaving the agent to infer usage context.

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