章节与元数据

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuine context about what is produced (ffmetadata / OGM chapter markup), but says nothing about behavior when a video has no chapters, whether pagination/season handling differs, or access limits — gaps that matter for an agent reasoning about failure modes.

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?

Two compact sentences; the core purpose and the available outputs come first, with the Bilibili-Evolved mapping as trailing context. Nothing is redundant, though the parenthetical about OP/ED could be folded more tightly.

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?

With no output schema, the description carries the burden of describing return shape, and it never says what the default `list` output looks like (field names, time units, whether entries include titles). For a read-only 3-parameter tool the remaining gaps are moderate rather than severe, but an agent cannot predict what it will receive.

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 67%, and the description usefully compensates for the one undocumented piece: the `format` enum has no schema description, but the text explains that list is chapters data while ffmetadata and ogm are chapter-file encodings for ffmpeg or OGM tooling. The `page` and `input` parameters are already documented in the schema, so no repetition is needed.

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?

States a specific verb and resource (获取视频的分段章节) and clarifies what chapters are in this domain (UP主设置的看点 / 番剧 OP、ED 时间), which rules out confusion with bili_danmaku or bili_subtitles. It also names the Bilibili-Evolved feature it mirrors. It stops short of naming any sibling tool explicitly.

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?

Usage is implied rather than stated: the mention of ffmetadata for ffmpeg chapter writing hints at when a caller would pick a non-default format. There is no explicit 'use this when…' or 'do not use this for…' guidance, and no pointer to bili_video_info or bili_danmaku as alternatives.

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