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

注解已经说明这是只读、幂等的操作；描述又补充了重要的额外行为：结果按最新在前排序，并且每次调用计费 1 次。它还说明了关键词匹配语义；对于这个简单搜索工具，这些信息已经足够明确。

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?

描述很简洁，并且先说明核心操作，再说明关键词匹配规则、排序规则和计费提示。几乎没有多余内容。

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?

对于使用 3 个参数、没有输出模式的简单搜索工具来说，描述已经覆盖了用途、关键词行为、排序和计费成本。次要的缺口是它没有说明返回哪些记录字段，但根据规则，这并不一定必需。

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?

输入模式对参数的说明覆盖率为 100%，因此参数含义的基线分数是 3 分。描述对核心的 `keyword` 参数补充了多于输入模式的信息，即最多 5 个空格分隔的词、所有词都必须包含；虽然它没有说明 `limit` 和 `since`，但这两个参数已经在输入模式中说明。

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?

明确写出了具体操作“搜”和资源“消息面记录”，因此作用很明确。它没有说明自己与相关兄弟工具（例如 get_news_stock_hits）的区别，所以没有拿到满分。

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?

用途由“按关键词搜消息面记录”隐含表达，搜索约束也很清楚：最多 5 个词，所有词都必须包含。但描述没有说明何时应使用这个工具、而不是其他新闻相关工具，也没有提及排除条件。

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