download_video

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says it downloads a video using yt-dlp and supports many sites. It does not mention whether downloads are synchronous, how long they might take, what the output is, error handling, or any side effects. This is minimal for a tool with no annotation support.

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 concise, using two short sentences with no fluff. It front-loads the primary action and intent, and the site support note is brief. It earns a 4 because it is well-structured and to the point, though it sacrifices depth for brevity.

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 12 parameters, no output schema, and no annotations, the description is inadequate. It does not explain what happens after download (return value, file path, errors), does not mention the option to extract audio or subtitles, and lacks any guidance on playlist handling or format selection. An agent given only this description would be under-informed for complex use cases.

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 has 100% description coverage, so all parameters are documented in the schema itself. The tool description adds no additional meaning beyond mentioning yt-dlp, which implies behavior but not parameter usage. Per baseline guidance, a score of 3 is appropriate when schema carries the parameter documentation.

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 a clear verb ('download') and resource ('video from a URL'), and identifies the underlying tool (yt-dlp). It also notes broad site support ('YouTube and many other sites'), which gives context. However, it does not distinguish this tool from its sibling 'download_stream', so the agent cannot tell them apart without additional investigation.

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?

There is no guidance on when to use this tool versus 'download_stream' or other siblings. The description only mentions broad site support, but does not state conditions, prerequisites, or when not to use it. An agent is left to infer usage from the name alone.

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