novel_chapter_brief

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

The description discloses a key behavioral trait beyond the schema: '只读不写盘（仅复用既有分析缓存）' – it is read-only and only reuses existing analysis caches. This is valuable because the tool name 'brief' doesn't imply read-only, and there are no annotations to carry this information. It also discloses that it aggregates from multiple sources. However, it doesn't detail what happens if the cache is missing or whether it can fail, so a 4 rather than 5.

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?

The description is a single dense paragraph that front-loads the core value proposition ('开写包：一次调用装配出...') and ends with the usage directive. It packs a lot of information efficiently, but the long enumeration of contents makes it slightly dense to parse. The key usage guidance is at the end rather than the beginning, which is a minor structural flaw.

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?

For a tool with 4 parameters, 100% schema coverage, and no output schema, the description covers the essential context: what it returns (the enumerated package contents), its read-only behavior, and when to use it. The main gap is that it doesn't describe the output format or how the returned package is structured, but since there is no output schema, the description partially compensates by listing the contents. It also doesn't mention error cases (e.g., missing chapter files), but this is a minor gap for an assembly tool.

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 description coverage is 100%, so the baseline is 3. The description adds context for the 'budget' parameter by explaining compact vs full in terms of context-saving ('按小额截断以省上下文' vs '给全'), and for 'chapter' by explaining the 'next' default behavior. However, it doesn't add meaning for 'book' or 'root' beyond what the schema already says. The description's main value is in explaining the overall purpose, not the individual parameters.

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?

The description uses a specific verb ('装配'/'开写包') and resource ('写这一章需要的一切'), then enumerates the exact contents (上一章结尾原文、本章大纲方向、人物卡、伏笔、世界观用语、六维风格基线、原著锚段、禁用清单、开写清单). This clearly distinguishes it from siblings like novel_read or novel_outline by stating it is a one-call assembly package rather than a single-purpose reader.

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?

The description explicitly states when to use it: '写新章前应先调它' (call it before writing a new chapter), and explicitly tells the agent NOT to use individual tools instead ('而不是逐个工具去翻'). This is a direct usage directive with an alternative-avoidance instruction, which is the strongest form of usage guidance.

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