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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds real value beyond them: per-call pricing (¥0.1), billing only on success, and automatic refund on failure or empty results — material facts an agent weighing repeated searches needs. Pagination depth and rate limits are still undisclosed.

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?

Four short sentences, front-loaded with purpose and return shape, then usage, then chaining, then cost. No filler and no repetition of the schema or annotations.

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 correctly compensates by naming the return contents and the downstream ID chaining. Billing terms and use cases round it out; only result-volume limits and paging behavior are left implicit.

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 keyword, page, order and _token are all documented in the schema itself. The description adds no syntax, format or default guidance for any of them, 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?

States a specific verb and resource ('B站综合搜索') and immediately describes the payload: a video list with per-item content ID and basic engagement metrics. This distinguishes it from bili_hot_search and bili_user_posts by implication, though it never names those siblings explicitly and '综合搜索' returning only videos is slightly loose.

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 concrete usage contexts ('关键词监测、内容发现或构建候选集') and explicitly tells the agent what to do next with the returned IDs (call detail and comment endpoints). It stops short of stating when NOT to use it, e.g. versus the hot-search sibling.

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