Upscale video

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

Annotations indicate readOnlyHint=false and destructiveHint=false, which are consistent with a tool that creates a new output. The description adds critical behavioral context: 'Paid render' informs the agent that this operation incurs cost, and 'returns the served URL' clarifies the return format. This goes beyond the annotations by disclosing financial impact and output type. It doesn't mention any potential delays or failure modes, but for a one-parameter tool, the added context is valuable.

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, dense sentence that conveys the action, resolution factor, usage context (final delivery), cost (paid), and the output (served URL). Every word adds value, and the most important aspects (action and purpose) are front-loaded. No wasted text.

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 one parameter and no output schema, the description covers the essential aspects: what it does, that it's paid, and what the return is. It doesn't mention whether the operation is synchronous or asynchronous, or any constraints on the input video (e.g., maximum resolution, format). However, given the simplicity, this is nearly complete and sufficient for an agent to decide when to invoke it. Minor gaps keep it from a 5.

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 covers the sole parameter 'video' with a description 'the source video URL' (100% coverage). The tool description does not add any parameter-specific details beyond what the schema provides, such as accepted formats, size limits, or how the URL should be hosted. Since schema coverage is high, the description meets the baseline but doesn't enrich parameter understanding beyond the schema.

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 states exactly what the tool does: 'Upscale a video to higher resolution (2x)' with a clear resource (video) and purpose ('for final delivery'). It distinguishes itself from siblings like clip_video, stitch_video, or edit_video by focusing specifically on resolution upscaling. This is a specific verb+resource pairing with no ambiguity.

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 phrase 'for final delivery' gives clear contextual guidance on when to use this tool (when preparing a video for final output). It also notes 'Paid render,' implying it should be used when the user is willing to pay for higher quality. However, it does not explicitly mention alternatives or when NOT to use it, such as if the video is already at the target resolution or if a cheaper preview is sufficient. This is slightly above average but lacks explicit exclusions.

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