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

No annotations are provided, so the description must disclose behavioral traits directly. It does this well by highlighting the key limitation: 'IMPORTANT: this only covers articles already cached by ReadGZH — WeChat has no public API for a full account archive, so the result is not exhaustive.' This is crucial non-obvious behavior beyond the basic action of listing. It also explains the reason, which helps the agent understand the tool's scope. It does not mention auth requirements or return format, but the main gotcha is covered.

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 three sentences, each with a clear purpose: the first states the core function, the second delivers the critical caveat in an 'IMPORTANT' callout, and the third provides a practical usage scenario. It is front-loaded with the action and resource, and there is no redundant filler.

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?

Given the tool's relative simplicity (2 parameters, no output schema), the description provides the essential context: what it does, its limitation regarding cached data, and when to use it. It lacks details about response format or pagination, but those are not required if not specified in the schema. The description is sufficiently complete for an agent to effectively select and invoke the 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?

The input schema already provides full descriptions for both parameters (account and limit), including defaults and partial-match support. The description itself does not add any parameter-specific semantics beyond referring to 'one Official Account', which aligns with the 'account' parameter. With schema_description_coverage at 100%, the baseline is 3, and the description does not elevate it further.

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 clearly states the tool's function: 'List cached WeChat articles published by one Official Account (公众号) via ReadGZH.' It names the specific resource (articles), the scope (one account), and the service (ReadGZH), which distinguishes it from sibling tools like 'list' (general) or 'search'. The usage sentence reinforces the purpose: 'Use it to find other articles by the same author after reading one.'

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 provides a concrete use case: 'Use it to find other articles by the same author after reading one.' It also sets expectations with the caveat that it only covers cached articles and is not exhaustive, which implicitly tells the agent when not to use it (e.g., when a full archive is needed). It does not explicitly name alternatives, but the context is clear.

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