get-bilibili-video-info

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

No annotations exist, so the description carries the burden of behavioral disclosure. 'Fetches' appropriately signals a read-only operation, but the phrasing 'and subtitles/captions' implies subtitles are always returned, whereas the schema shows includeSubtitles defaults to false and requires SESSDATA. The description does not mention authentication, rate limits, or that subtitle inclusion is optional, leaving some ambiguity.

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?

A single sentence with no filler, front-loading the main action and then expanding with a parenthetical field list. Every word contributes to the agent's understanding, and the structure is easy to parse.

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 simple two-parameter metadata fetcher with an output schema present, the description plus schema covers the essentials. What is missing is an explicit qualifier that subtitles are optional and not returned by default; that detail lives only in the schema, so the description could mislead an agent that does not inspect parameter defaults closely.

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 input schema already describes both parameters fully, including the url format example and the includeSubtitles default/requirement. The description adds no parameter-level detail beyond what the schema provides, so the baseline 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 states a specific verb ('Fetches') and a specific resource ('Bilibili video metadata'), and enumerates the exact metadata fields it returns: title, author, duration, description, publish date, view count, plus subtitles/captions. There are no sibling tools to distinguish from, so this is as clear as needed.

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 makes the tool's purpose clear, so an agent can infer when to use it: whenever Bilibili video metadata or subtitles are needed. It does not explicitly state exclusions or alternatives, but with no sibling tools, the lack of explicit when/not guidance is less critical.

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