download_video

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

No annotations, so the description carries the full burden. It usefully discloses the default save location, but says nothing about overwrite behavior when the file already exists, permissions, or whether the download is reversible — notable gaps for a tool that writes to disk.

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?

Short, front-loaded, and the Args block maps directly to the schema with zero filler. The parenthetical default-path note earns its place.

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?

With only two parameters, both documented, an output schema covering return values, and the default destination disclosed, the agent has enough to invoke it correctly. The missing piece is collision/overwrite behavior on an existing file.

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 0%, so the description must compensate, and it does: it explains both parameters, notes filename is optional and shows a concrete example ('fox.mp4'), and identifies the valid source of video_url. Only format expectations for video_url (URL vs. ID) are left unstated.

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?

States a specific verb and resource ('Скачать готовое видео на компьютер') plus a concrete default destination folder. Sibling differentiation is implicit rather than explicit: it names generate_video and check_video only as URL sources, not as tools to prefer for other tasks.

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?

Gives a clear precondition — the video_url must come from generate_video or check_video — which tells the agent where this tool fits in the workflow. It does not state when not to use it or what to do on failure, so no explicit exclusions.

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