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

Annotations already declare this is a non-read-only, open-world, non-idempotent but non-destructive operation, so the safety profile is covered. The description adds value by stating that the tool returns the optimized prompt (its output contract) and that mode tailors the underlying skill, though it does not mention cost or latency for what is effectively an LLM skill invocation.

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?

Three tight sentences with no filler: the action and return value come first, then the mode semantics. Every sentence carries distinct information.

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?

There is no output schema, and the description states the return value is the optimized prompt, which is sufficient. For a two-parameter skill with one enum, the description covers what an agent needs to call it correctly, though mentioning the input length cap would round it out.

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?

With 0% schema description coverage, the description carries the burden and mostly does: it enumerates all four mode values and explains that mode tailors the skill, and clarifies that prompt is a short idea being expanded rather than a finished prompt. The only unexploited detail is the 10,000-character input limit, a minor omission.

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?

States a specific verb and resource: it runs VidGuy's SeedDance 2.0 prompt-engineering skill to expand a short idea into a production-grade prompt, and explicitly returns the optimized prompt. This clearly separates it from sibling generators like seedance_generate_video or seedance_generate_image, which produce media rather than prompts.

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 phrase 'before generating' gives a clear sequencing context for when to call it, and the mode list hints at which generation path each mode serves. It stops short of naming excluded alternatives or stating prerequisites, so it is clear context without explicit when-not guidance.

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