get_danmaku

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

No annotations exist, so the description carries the burden. It usefully discloses one behavioral trait beyond the schema — out-of-range page raises an explicit error rather than silently falling back to P1 — and states that output is a compressed summary, not raw danmaku. However it says nothing about volume, rate limits, or what happens with empty danmaku streams, and an output schema already covers the return shape.

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?

Front-loaded with the action and output, then rationale, then constraints. The rationale section is somewhat editorial and could be tightened, but every paragraph maps to a decision the caller must make.

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?

Return values are covered by the output schema, and the description adds scope restrictions and error behavior, which is what an agent most needs for a focused analysis tool. The gap is that 'top' is undocumented, leaving one of three parameters opaque.

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 0% and there are 3 parameters, so the description must compensate. It does well for page (multi-P selector, default 1, hard error on out-of-range), but 'top' (default 5) is never explained and bvid is left implicit. Partial compensation only.

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?

Names a specific verb and resource (get danmaku) and immediately enumerates the derived outputs: density curve, densest segment with samples, high-repetition lines, disclosure keywords. It also explicitly contrasts itself with get_comments (second-level timestamps vs publish time), so an agent can tell them apart without opening the schema.

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?

Gives an explicit two-item allowlist of use cases (extension divergence, comment-section structural bias) plus two explicit prohibitions: don't create a dedicated chapter, don't treat danmaku as majority opinion. That is when-to-use, when-not-to-use, and the alternative (get_comments) in one place.

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