get_video_info

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

No annotations are provided, so the description carries full burden. It reveals the return priority but does not disclose credential requirements beyond a vague reference, rate limits, failure modes, or whether the tool is read-only. The behavior is partially transparent but lacks safety and side-effect details.

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 extremely concise with two Chinese sentences and one English sentence for credentials. All essential information is front-loaded, and every sentence serves a purpose (core functionality, fallback behavior, parameter support, credential guidance). No wasted words.

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?

Given the absence of an output schema, the description adequately explains return values (subtitle or fallback). It covers the main parameters and alludes to credential needs. However, it lacks details on error handling, response format, and pagination, which are minor gaps for a simple info tool.

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 100% with parameter descriptions. The description adds value by explaining that preferred_lang and page work together in the priority logic, reinforcing their semantics beyond the schema. This justifies a score above baseline 3.

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 purpose: 'get Bilibili video info' with a specific return priority: subtitles first, then description/tags. It also mentions support for preferred language and multi-P episodes, effectively differentiating from sibling tools like get_video_transcript and get_video_metadata.

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 description does not explicitly compare this tool to siblings or state when to use alternatives. The credential help note is about setup, not usage context relative to other tools. Without guidance on when to prefer this over get_video_comments or get_video_chapters, the agent is left to infer usage.

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