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

No annotations are provided, so the description carries the full behavioral burden. '详情' weakly implies a read-only lookup, but there is no disclosure of auth requirements, rate limits, whether the call is safe/idempotent, or what the returned payload contains. For a zero-annotation tool this is a substantial gap.

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?

Four characters, no padding and fully front-loaded, which is efficient. But at this length the brevity reflects under-specification rather than disciplined conciseness, so it does not earn a top score.

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 is simple (2 params, no nesting, no output schema, no annotations), so a short description could suffice — but the agent still lacks any statement of what the response contains or how it differs from the ~8 sibling video-detail tools. Barely adequate for the 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 100% — both photo_id ('视频ID') and the fallback _token are documented in the schema itself, including the X-FW-Token alternative. The description adds no parameter meaning beyond that, so the baseline of 3 applies.

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 names the resource (快手视频) and implies a retrieval ('详情'), so an agent knows this fetches Kuaishou video details. However it never states the verb explicitly nor distinguishes itself from the many sibling *_video tools (douyin_video, tiktok_video, yt_video, bili_video) beyond the implicit platform prefix in the tool name. Purpose is identifiable but generic.

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?

No guidance on when to use this tool versus the other platform video tools, no prerequisites, no mention that a video ID is required. The agent must infer everything from the name and schema.

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