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

没有注解，描述承担全部行为披露责任。它提到了数据源（Frankfurter和备源），这提供了背景，但未说明返回格式、错误处理、速率限制或数据源切换的影响。对于实时汇率工具，这些信息可能影响调用决策。

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?

描述简洁，两句话涵盖了主要功能和参数说明，没有冗余。但可以更结构化地分条列出参数行为，不过整体已足够高效。

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?

无输出模式，描述未说明返回数据的结构或格式。虽然解释了基本行为，但对于一个涉及数据源的实时工具，缺少关于返回内容、错误处理或数据源切换的细节，完整性中等。

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?

模式描述覆盖率为0%，描述完全弥补了这一点。它解释了base（基准货币代码或中文名）、target（目标货币，留空返回常用汇率）和amount（可选换算金额），为每个参数提供了明确语义，远超模式本身的默认值。

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?

描述用具体动词'查询'和资源'汇率'明确了目的，并说明了可进行金额换算。虽然没有同级工具需要区分，但表述清晰，足以让智能体理解工具的核心功能。

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?

描述未提供何时使用此工具的明确指导，也没有提及替代方案或排除条件。虽然说明了target为空时的行为，但缺乏使用场景或前置条件的说明。

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