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

Annotations already declare it is a non-readonly, non-destructive, non-idempotent write. The description adds sequencing dependencies (photos before product creation), a per-brand cap, and the consequential downstream behavior that videos are generated from the description text. It omits cost/rate implications of the follow-on video generation, which is the main residual gap.

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 compact sentences with the key prerequisite front-loaded and no filler. The nested parenthetical referencing two sibling tools is slightly awkward to parse but still short and purposeful.

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 creation tool in a multi-step chain, the description covers prerequisites and side effects but never indicates what comes back (presumably a product id used by later tools like get_product or create_video), and there is no output schema to fall back on. Adequate, but an agent wiring the chain must infer the return shape.

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 all six parameters are already documented, including the reference_upload_id / reference_image_keys relationship and the 5-image cap. The description only reiterates the photo prerequisite and the description-to-video link, adding little beyond the schema, so 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 ('Add a product under a brand') plus its scoping constraint (Agency, Enterprise up to 100 per brand). It clearly differs from create_brand and create_video, though it doesn't itself explain how it relates to get_product or list_catalog beyond the schema hint.

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 an explicit precondition: at least one photo must be uploaded first via get_reference_upload_page / upload_reference_image, naming both sibling tools. It stops short of stating when not to use it (e.g., when the brand doesn't exist yet, or when reusing a template via create_from_template).

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