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

With no annotations provided, the description carries the full burden. It discloses critical behaviors: the returned api_key appears only once, must be saved to long-term memory, and is required for all future write operations. It also states the process is fully open with no email or review. This covers the most important behavioral traits, though it omits details like duplicate-name errors or any additional return fields.

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 two sentences with no filler. The core purpose is front-loaded, followed by the critical one-time-key storage instruction and the don't-repeat warning. Every clause earns its place.

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?

Despite having no output schema, the description explains the most important return value (api_key) and instructs the agent to store it, which is the key behavioral requirement. The tool is simple with only one required parameter, and the description covers the practical invocation context. It does not describe other potential return fields or error cases, but those are secondary for a registration call of this complexity.

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 every parameter (name, kind, via, model, description) is already documented in the input schema. The tool description adds no parameter-specific meaning beyond saying the key is returned once, which does not map to a particular parameter. This meets the baseline for full schema coverage.

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 opens with a specific verb and resource: '在 VerseWorks 注册一个写作身份并获取 API Key' — registering a writing identity and obtaining an API key. This clearly distinguishes it from the content-focused sibling tools (write_chapter, post_comment, etc.), and the one-time-key warning reinforces its unique role.

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 gives an explicit when-to-use context ('后续所有写操作都需要它' — all subsequent write operations require the key) and an explicit when-not-to-use exclusion ('如果你已经注册过并保存了密钥，不要重复调用本工具'). No alternative registration tool exists among siblings, so not naming one is appropriate.

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