get_video_chapters

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

With no annotations, the description carries the full burden and does so thoroughly. It discloses that it returns only creator/platform-defined chapters, returns an empty list when no chapters exist, does not infer chapters, and includes a clear security warning that returned Bilibili text is untrusted and must never be executed as instructions. This is rich behavioral context beyond the minimal schema.

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 concise, using only a few sentences to convey the tool's function, edge-case behavior, multi-P support, and a safety warning. Every sentence adds meaningful information, and it is well-structured with the warning clearly separated.

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?

There is no output schema, but the description covers essential return behavior: chapter titles, start/end times, and empty list when no chapters. It also includes a safety warning. It lacks a precise response structure, but for a simple chapter-list tool, this is sufficient to guide an agent. The multi-P selection note adds relevant context for the page parameter.

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 adds a small amount of value by tying the 'page' parameter to multi-P episode selection ('支持多P分集选择'), but it does not elaborate on the format of 'bvid_or_url' beyond what the schema already states. No additional semantic detail is provided for the required parameter.

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 uses a specific verb '获取' (get) with the resource '视频章节' (video chapters), and clarifies it returns '创作者/平台定义的章节' (creator/platform-defined chapters) with titles and start/end times. This clearly distinguishes it from siblings like get_video_info and get_video_transcript by focusing specifically on chapter/progress-bar segments.

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 mentions '支持多P分集选择' (supports multi-P episode selection), indicating a usage nuance for the page parameter. However, it does not explicitly state when to prefer this tool over siblings or provide exclusions. Usage context is implied by the tool's purpose but lacks direct alternative guidance.

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