xhs_generate_cover

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

No annotations are provided, so the description carries the full behavioral burden. It discloses the core behavior (generates an image and returns a URL), which is more than a bare 'generate' tautology. However, it does not mention whether credit is consumed, whether generation is asynchronous, or whether the URL expires, which are relevant behavioral traits for a generation tool.

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?

One short sentence with no wasted words, front-loaded with the primary action and including the key input and output information. It is concise and well-structured.

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?

The description explains the return value (image URL), which is important because there is no output schema. However, it omits usage context such as credit costs, possible async behavior, and when to prefer this tool over siblings. Basic information is present, but important context is missing.

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 both 'text' and 'aspectRatio' are already documented with descriptions and an enum. The description only repeats the text-to-image idea and adds no parameter details beyond the schema, so the baseline 3 applies.

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 states a specific action ('generate') and resource ('Xiaohongshu-style cover image'), and explicitly mentions the input (text) and output (image URL). It is clearly distinct from the sibling tools, which deal with credits and history.

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 does not provide any guidance on when to use this tool versus alternatives. It does not mention the sibling tools, prerequisites, or whether credits are required, leaving the agent to infer usage from the tool name alone.

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