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

注解已经声明 readOnlyHint=true、idempotentHint=true、destructiveHint=false，因此安全画像由注解承担；描述额外补充了登录时附带 myRating、站内口碑刚起步导致多数产品为空返回等注解未覆盖的行为特质。这些信息有助于代理正确解释返回结果，但未涉及分页/游标行为，不过 schema 已覆盖。

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?

描述用三段式组织：核心功能 → 口径/空结果提醒 → 写评价入口，核心信息置于开头，每条都有实际价值。没有冗余从句或重复 schema 内容，长度紧凑，可读性强。

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?

虽然没有输出 schema，但描述明确说明了返回结构（星级汇总 + 评价列表）以及登录后额外附带 myRating，足够代理理解结果。空返回的常态性提示也很关键。唯一欠缺的是未提及同族工具 get_product_rating_summary 可用于仅获取汇总的场景，但对完成本工具的调用目标而言已足够完整。

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?

输入 schema 的字段覆盖率为 100%，productId、sort、limit、cursor 都已有明确描述，因此描述无需重复参数含义。描述中“登录时附带 myRating”属于输出行为而非参数语义，没有为参数增加额外解释，按基线评 3。

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?

描述以明确动词“返回”+ 资源“某产品的口碑”开头，并具体列出返回内容（星级汇总 + 评价列表），让代理立刻知道工具做什么。它还通过与 get_product（不含评价）和 rate_product（写评价）的对比，进一步界定了自己的定位，虽然未显式提及 get_product_rating_summary，但“汇总 + 列表”的组合已经足够清晰。

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?

明确说明使用场景：“get_product 详情不含评价，要口碑必须调本工具”，并给出写操作的替代工具 rate_product。还专门提示“绝大多数产品是 0 条评价——空返回是常态，不是查询失败”，防止代理误判空结果并反复重试或去站外找数据，这是非常实用的使用边界。

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