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

Adds substantial behavior beyond the annotations: it runs in the background for minutes, lands in the Todo list, returns a post id and task id, and must be verified via get_task_status ('never say it is done'). It also discloses the cost/quality tradeoff between 'designed' and 'simple' looks, which no annotation conveys.

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?

Front-loads the outcome ('Make a short vertical video...') before the option lists. The dense parenthetical enumerations make the middle heavy and slightly run-on, but nearly every clause carries operational 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?

For an async, open-world creation tool with no output schema, the description covers what is produced, how long it takes, where it lands, what identifiers it returns, and how to confirm completion. An agent has everything needed to call it and follow up correctly.

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 coverage is only 60%, and the description compensates by explaining the semantics of the enum values — sound options and their meaning, 'look' default (designed) with a concrete description of the cheaper 'simple' mode, and the first-photo rule for multi-product runs. 'steer' and 'targetDuration' are left to the schema, but the description clearly adds meaning over the raw enums.

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 ('Make a short vertical video (Reels/TikTok) out of one or more products from list_products') and pins the source of the inputs. This clearly separates it from siblings like create_photo_reel or create_post_from_video, which are not product-based.

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?

Gives useful preconditions ('Needs at least 2 product photos in total', productIds come from list_products) and post-invocation guidance, but never states when to prefer this tool over create_photo_reel, generate_from_product, or create_video_shoot. Usage is implied rather than routed.

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