bilibili_video_get_download_info

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It mentions the return contents (download links, quality list, player config) but does not disclose important behaviors such as whether authentication is required, whether download links expire, or any error conditions. This is a significant gap for a tool that returns potentially sensitive or time-limited data.

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 and well-structured, with a front-loaded purpose statement followed by clearly labeled Args and Returns sections. Every sentence contributes necessary information, with no 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?

The tool has no output schema, so the description must explain return values; it does provide a summary ('包含下载链接、清晰度列表、播放器配置等信息') but remains vague with '等信息' (and so on). Given the tool's moderate complexity and lack of annotations, the description covers the essentials but lacks detail on return structure, error handling, and special conditions, making it adequate but incomplete.

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 has 0% description coverage, but the description fully compensates by explaining both parameters: 'bvid: 视频的BV号' and 'page_num: 分P序号，从0开始' (part index starting from 0). This adds clear meaning beyond the bare schema and clarifies the default behavior of page_num.

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 tool's function: '获取视频下载链接和播放器信息' (get video download links and player info). This is a specific verb-resource pair and distinguishes it from sibling tools like bilibili_video_get_info or bilibili_video_get_danmaku, which serve different purposes.

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 usage is implied by the purpose: when a user needs download URLs or player configuration for a Bilibili video, this tool is appropriate. However, there is no explicit mention of when not to use it or which alternative tools to consider instead, leaving some ambiguity in choosing among video-related tools.

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