子账号带宽趋势

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

注释已声明readOnlyHint=true、idempotentHint=true等，描述未与注释矛盾，也未添加额外行为（如权限、返回格式）。描述仅解释trend_type参数行为，这属于参数语义而非工具行为，因此符合注释覆盖下的基线水平。

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?

描述为单句，直接点明核心功能，并快速嵌入两种模式及时间约束，无冗余信息，信息密度高且结构清晰。

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schema，描述未说明返回内容（如返回趋势数据格式或单位）。对于调用，参数和约束已覆盖，但返回信息缺失可能影响代理对结果的解释，因此完整性不足。

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?

schema对参数描述覆盖100%，每个参数均有说明。描述额外添加了'跨度不超过31天'的约束，这是schema未提供的，增加了价值。但未对参数格式做更多补充，因此高于基线但非满分。

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?

描述明确说明查询子账号带宽趋势，并区分实时（trend_type=1）和历史（trend_type=2）两种模式，动词'查询'+资源清晰。但未与兄弟工具如bandwidth_detail做区分，可能产生混淆，因此不达满分。

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?

描述给出了两种trend_type的使用方式，并明确历史查询需传startTime、endTime且跨度不超过31天，提供了清晰的操作上下文。但未提及何时使用此工具而非其他兄弟工具（如bandwidth_detail），缺乏排除性指导。

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