Download a user-provided public video

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 reveals that the video is saved to a private local folder, that the URL is treated as authorized, and that the tool will not circumvent protections. This gives the agent a clear model of the tool's safety boundaries, which is valuable beyond the input schema alone.

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 two sentences, with the primary action front-loaded and the constraint sentence adding necessary guidance. Every word earns its place; no filler or repetition.

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 simple one-parameter tool, the description covers purpose and constraints, but it omits any information about the return value or outcome (e.g., whether it returns a file path, success message, or error). Since there is no output schema, this gap makes the description only minimally complete for an agent that needs to know what to expect after invocation.

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 schema already fully describes the 'url' parameter with 100% coverage (format, type, description). The tool description adds that the URL is 'user-provided' and 'authorized', which is mild extra context but not essential. The baseline of 3 applies because the schema does the heavy lifting.

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 action ('Download a user-provided public video') and the destination ('Video Intelligence's private local downloads folder'). This distinguishes it from sibling tools like analyze_video and ask_video, which operate on videos already available.

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 when to use the tool (downloading public videos) and includes an explicit exclusion: 'do not bypass DRM, paywalls, logins, private links, or platform protections.' It does not name alternative tools, but the sibling list makes it obvious that this is the download step before other operations.

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