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

Annotations already mark this as a non-read-only, non-idempotent operation, and the description adds two facts annotations cannot convey: it 'spends a few of the account's credits' and it returns a job whose result holds the script (implying the async get_job/wait_job pattern). It does not describe failure modes, rate limits, or what an in-progress job looks like.

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?

Two dense sentences with no filler; the core action and the credit cost are front-loaded and the parameter-conditioning guidance follows. Is slightly run-on but 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?

For a 12-parameter, zero-required, multi-mode tool with no output schema, the description covers what matters: the mode-selecting parameters, the cost, and the fact that the return is a job holding the script. Nothing critical is missing, though a pointer to the job-retrieval sibling would have closed the loop.

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 100% schema coverage the individual parameters are fully documented, so the baseline would be 3. The description adds real semantic value by explaining that hooks and translate_to are mode selectors that only apply when script is supplied, a conditional relationship the flat schema cannot express.

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 (writes) and resource (ad script), and enumerates the three distinct modes: new script from product/page_url, alternative hooks from a saved script, and translation. It is clear enough that an agent knows what it will get back, though it does not name which sibling to prefer (e.g. ugcfans_make_ad) for overlapping ad-writing needs.

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?

Explicitly conditions the modes: 'Give product or page_url to write a new script; give script with hooks (how many) or with translate_to (a language) to work on one.' This tells the agent exactly which parameter combinations select which behavior. It stops short of saying when NOT to use this tool versus the other ad-making siblings.

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