download_video

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

Adds valuable behavioral context beyond the annotations: the side effect of saving to VIDEO_PATH, the failure condition if the video isn't completed, and the return format (filename, variant). This goes beyond the readOnly/idempotent hints.

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 well-structured with a clear opening, warnings, parameter explanations, and a numbered workflow. Every section earns its place, and the information is easy to scan.

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?

Despite no output schema, it explains the return value (DownloadResult with filename, variant) and provides a full workflow. It also covers the key precondition and file destination. The description is complete for this tool's complexity.

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 description coverage is 0%, but the description compensates by explaining every parameter in detail: video_id's source, filename's default behavior, and all variant enum values with their meanings. This adds significant meaning beyond the bare 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 opens with a specific verb and resource: 'Download a completed video to disk.' It clearly distinguishes this tool from siblings like view_media (preview) and list_videos (listing) by specifying the action and output (file on disk).

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 provides explicit when-to-use conditions ('Only call this AFTER get_video_status shows status=completed') and a typical workflow. However, it does not explicitly name alternative tools for related tasks (e.g., view_media for preview), so it lacks explicit alternatives.

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