analyze_image

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

无注解，描述承担了行为透明度责任。它说明了返回 dict 含 model/content/reasoning/elapsed_ms 字段、失败时会抛异常、thinking 开启时附带思考过程。但未提及图片格式/大小限制、网络依赖或外部 API 调用风险，留有轻微缺口。

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?

描述采用目的/适用/Args/Returns 分段，结构清晰、无冗余。示例 prompt“提取图中所有文字，保留排版顺序”提供了额外价值，且整体长度适中。

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 5 参数、无输出 schema、无注解的工具，描述覆盖了所有参数、返回值、异常行为和使用场景，已相当完整。但缺少图片大小限制、网络连接要求等边界条件，存在小幅遗漏。

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 描述覆盖率为 0%，描述完全补偿了这一点：images 明确支持本地路径、URL、base64；prompt 给出语义和示例；temperature 说明范围与确定性影响；max_tokens 和 thinking 均给出默认值和含义。参数解释远远超出 schema 标题。

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?

描述明确以“调用智谱 GLM-4.6V-Flash 分析一张或多张图片”给出具体动词、资源和模型，并列出图片描述、OCR、表格解析等使用场景，与兄弟工具 check_config 区分明显。目的清晰且无歧义。

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?

描述提供了“适用：图片描述、OCR 文字提取、表格/图表解析、UI 截图理解、多图对比等”场景列表，说明何时使用。但未明确点名替代工具或给出“不要用于……”的排除条件；不过兄弟工具仅 check_config，上下文已足够区分。

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