Research a Bilibili Video

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

With only readOnlyHint=true in annotations, the description adds substantial behavioral context: it promises public metadata and an explicit community-context status, and specifies the comment sampling and display policy in detail. That goes well beyond the annotation and helps an agent understand what the tool will actually do with community 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 two sentences with no wasted clauses, front-loading the resolution behavior and return guarantees before covering research modes. The detailed comment sampling figures are dense but purposeful and easy for an agent 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 an 8-parameter tool with a nested source_quality object and no output schema, the description covers the main return behavior and the unusual comment-sampling policy. It could still be more explicit about the shape of public metadata and community-context status values, but the schema fills in most parameter details.

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%, so the baseline is 3. The description reinforces the mode choices and comment-sampling behavior, but adds little new parameter semantics beyond what the schema already documents for url, mode, include_comments, interval, and source_quality.

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 action and resource: resolving a public Bilibili URL and returning metadata plus optional comment context, with modes for language, vision, and multimodal research. It clearly distinguishes the Bilibili-specific scope, but does not explicitly contrast it with siblings such as analyze_video_url or analyze_video.

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 usage through the supported research modes and the requirement for a public Bilibili URL, but gives no explicit when-to-use guidance, exclusions, or comparison to the sibling tools. An agent must infer when this tool is preferable to generic video tools.

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