generate_cover

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

With no annotations, the description carries the behavioral disclosure burden. It does add one useful behavioral trait: '按用量后付' ('billed by usage after the fact'), warning that invocation may incur cost. However, it does not disclose whether generation is synchronous, whether it creates or replaces an existing asset, what output the caller receives, or any permission requirements, so transparency is only partial.

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 short and front-loaded with the main purpose, but the second part '图片步,按用量后付' is grammatically awkward and likely contains a typo ('步' appears to be '按' or a mis-split phrase). The billing note could be clearer, so the text is concise but not cleanly 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?

For a tool with no annotations, no output schema, and only one parameter, the description gives the basic action and billing note but omits important operational context: expected return value or job ID, asynchronous behavior, cost magnitude, and when to prefer this over generate_drama_poster or generate_episode_poster. An agent would likely struggle to know what to do with the result or whether this is the correct 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 0%, so the description must compensate for the single drama_id parameter. The phrase '整部剧' helps clarify that drama_id refers to a whole drama rather than an episode, which is useful given many sibling tools are episode-scoped. But it does not explain the parameter format, how to obtain the ID, or what value is expected, leaving the agent to infer most parameter semantics from the schema's integer/exclusiveMinimum constraints.

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 verb and resource: '给整部剧生成片头封面图' ('generate the opening cover image for the entire drama'). It is clear this is a generation action scoped to a whole drama, which helps separate it from episode-level tools. However, it does not explicitly distinguish itself from similar siblings like generate_drama_poster or generate_episode_poster, so it stops short of a 5.

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?

There is no guidance about when to use this tool versus alternatives. No exclusions, no references to sibling tools, and no context about whether this is the right choice for a drama cover versus a poster. The scope '整部剧' is implicit but no explicit selection criteria are provided.

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