download_video

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

With no annotations provided, the description carries the full burden. It does disclose the return type (base64-encoded binary data) and the precondition, which is useful. However, it does not specify behavior on failure, such as what error occurs if status is not completed, or whether the download is read-only. These are minor gaps for a download operation.

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 concise sentences. The first sentence states the core action and variants; the second provides the critical condition and return format. There is no filler or redundant content.

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 download tool with only two parameters, this description is complete. It covers the resource types, the precondition, and the return format. The absence of an output schema is compensated by the explicit mention of base64-encoded data. Sibling tools are clearly different in purpose, so no additional context is needed.

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 coverage is 100%, so the baseline is 3. The description goes beyond by mapping each variant to its format (video=MP4, thumbnail=WebP, spritesheet=JPEG) and adds the completed-status condition for video_id. This enriches the schema's terse definitions.

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 uses the specific verb 'Download' and clearly identifies the resources (video, thumbnail, spritesheet) with their formats (MP4, WebP, JPEG). This completely distinguishes it from sibling tools like delete_video or create_video.

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?

It states the explicit precondition 'Only works when status is completed', which guides the agent on when it is appropriate to call. It does not explicitly name alternatives like get_video_status for checking status, but the condition implies the need to check first.

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