upload_video

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

没有 annotations，描述承担了全部行为披露责任。它详细说明了预签名地址 10 分钟有效期、uploadCommand 必须原样执行、Content-Disposition 不能改动否则 S3 报 SignatureDoesNotMatch，以及视频与文档不同端点/存储路径。这些都是调用成功与否的关键行为约束。

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?

描述主功能放在首句，随后是必要的执行警告、时效提醒、工具边界和后续步骤，信息密度高且每句话都有明确作用，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?

在无输出 schema 的情况下，描述充分说明了返回值的用法（uploadCommand、objectKey）、上传约束、有效期、与 upload_document 的边界，以及如何衔接 translate_video。agent 依据描述即可正确走完整个上传流程。

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?

唯一参数 file_name_list 在 schema 中已有 100% 描述（“视频文件名列表”），描述正文没有补充格式、扩展名或列表约束。按高 schema 覆盖率基线评 3 分，描述没有增加超出 schema 的语义。

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?

描述以明确的动词和资源开头：“取视频的预签名上传地址”，清楚说明工具职责。同时通过“视频不能用 upload_document 取链接”与同名兄弟工具做了区分，agent 不会混淆工具用途。

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?

描述明确给出使用时机和完整工作流：取到地址后立即上传、只替换文件路径、上传成功后用 objectKey 调 translate_video；还显式排除上传文档场景。对何时用、何时不用、后续步骤均给出可执行指引。

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