nexus_get_download_link

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

注释已声明readOnlyHint=true和destructiveHint=false，因此描述无需重复安全概况。它增加了有价值的行为上下文：URL是短时有效的、不应缓存、返回镜像列表且第一个位置是首选。

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?

描述简短且前置了核心目的，然后以有用的结构呈现认证要求，最后以返回格式和缓存警告收尾。每个句子都贡献了操作所需的信息，没有冗余。

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?

对于具有5个参数、账户特定行为和现有输出schema的工具，描述覆盖了所有关键方面：用途、认证变体、必需参数来源、返回结构以及缓存限制。没有遗漏任何关键信息。

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的覆盖率为100%，参数描述已经解释了key和expires的来源、required条件、domain_name格式以及数值ID。描述在参数语义方面没有显著增加超出schema的内容，因此基线3是合适的。

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?

明确且具体的动词+资源：从Nexus CDN获取mod文件的短时下载URL。这将其与返回文件信息或直接下载的兄弟工具区分开来，并说明了它是什么（URL、非文件内容）。

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?

提供了明确的实用条件：高级账户可省略key/expires，非高级账户必须从.nxm链接提取。虽然没有明确命名替代工具或'何时不使用'，但前提条件和所需参数来源已清晰陈述。

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