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

Annotations only mark it as a non-read-only open-world write. The description adds real behavioral context beyond that: the operation is free but consumes a quota shown by get_balance as scripts_left, the scripts are authored by the provider's own writer and held to the product facts, and the call is asynchronous, returning an id immediately with a ~1-minute polling cadence against get_scripts. That is exactly the cost, provenance, and async-lifecycle information an agent needs.

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?

Four sentences, front-loaded with the purpose, then provenance, cost, and the async follow-up in that order. Nothing is padded, though the second and third sentences could be tighter and the key polling instruction sits at the very end.

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 14-parameter, no-output-schema tool, the description covers the essential lifecycle: what it produces, that it is quota-metered, and that results must be fetched via get_scripts rather than returned inline. It does not describe what the returned scripts contain, but that gap is largely covered by the schema's lines rules and the get_scripts sibling.

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 every one of the 14 parameters is already documented in the schema, including the mutually exclusive constraints on ad/angle/lines/script_id. The description adds only the loose note that scripts derive from the read_product read; it adds little parameter meaning 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?

States a specific verb and resource: write three scripts for a UGC video of a product. It also positions itself relative to siblings, naming read_product as the fact source and get_scripts as the status poller, so an agent can separate it from the read and fetch tools without opening a schema.

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?

"to read before making one" gives clear sequencing guidance (run this before make_video), and the follow-up instruction to poll get_scripts about once a minute until ready or failed is explicit. It stops short of naming when to prefer alternatives such as change_video or another_language, so it is clear context without exclusions.

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