bilibili_video_playurl

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

Annotations already cover read-only, idempotent, non-destructive, and open-world behavior. The description adds important runtime behavior beyond that: the returned URLs are temporary, time-limited, and tied to the current session's playback context.

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 a single tightly written sentence with the key behavior front-loaded. The '[视频]' prefix and the expiry warning are useful and carry no wasted text.

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 five-parameter tool with no output schema and no schema parameter descriptions, the definition is too sparse. It conveys the broad result type and URL expiry, but leaves parameter meanings, quality/format controls, and actual response structure unclear.

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% across five parameters, so the description must compensate, but it names no parameters and does not explain bvid, cid, qn, fnval, or fourk. The only relevant hint is '清晰度', which loosely relates to quality but does not clarify how qn or the format parameters work.

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 specific verb and resource: obtain temporary playable media URLs and quality for the current session. The '[视频]' tag helps distinguish it from live playurl tools, but no sibling tool is named and the distinction from tools like bilibili_video_info is only implicit.

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 implies the tool is for getting playable media addresses, but gives no explicit when-to-use guidance, no alternatives such as bilibili_video_info or bilibili_video_pages, and no stated prerequisites beyond the vague 'current session' scope.

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