会话详情

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

没有注解，所以描述承担了披露行为特征的全部责任，并且确实披露了关键操作形态：约 20KB 的默认截断上限、单条截断长度，以及 session_id 支持前缀匹配。缺失的是返回内容形态和权限要求，但对读取工具来说，关键约束已经交代清楚。

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?

三段式短句，先说作用，再说默认安全上限，最后说如何扩量，没有废话，并且安全默认值前置。

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?

7 个参数、无输出 schema、无注解；描述覆盖了主要行为约束与扩量路径。仍缺少返回结构说明，对首次调用者存在少量不确定，但整体足够调用。

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 描述覆盖率已达 86%，分数线是 3；描述还补充了 max_chars 的默认值、用 start_msg/end_msg 扩量这一条件，以及 session_id 支持前缀匹配，这些在 schema 中并不都被体现。因此略高于分数线。

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?

具体动作加资源：取某会话的消息，并附带过滤范围（按角色过滤、限制范围与长度）。相比 get_linked_sessions、search_sessions 这类兄弟工具，它没有明确区分，但核心目的没有歧义。

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?

清楚说明默认安全行为最多 20 条 × 1000 字 ≈ 20KB，并指出需要更多数据时显式传 start_msg/end_msg 或 max_chars 来扩大范围。这给出了明确的分页和扩量上下文，但从未说明什么时候改用 search_sessions 或 list_sessions。

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