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

Annotations only declare write/non-idempotent/non-destructive; the description adds real value on top: zero cost, per-image size cap of 15 MB, a cap of 5 extra images, the fact that extra angles improve accuracy, and a failure mode with prescribed follow-up. It does not address duplicate-product behavior or where the product lands, which is notable given sibling folder/move tools.

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-loaded with the creating action and input modes, and every clause carries information (limits, outputs, error path, worked example). The cost is a single very long sentence with nested parentheses that is harder to scan than it needs to be.

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?

With no output schema, the description carries the return-value burden and does so: product id, the analysis fields (name, category, materials, colours, selling points, recipe, label facts), up to 5 missingFacts, and the ok flag. Only organizational behavior after creation is left unspecified.

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 already 100%, so the baseline is 3, but the description adds meaning the schema lacks: the 15 MB limit per photo, the accepted formats (JPG, PNG, WebP), that a data: URL prefix is acceptable, and that more angles improve analysis quality. The photos-vs-URL tradeoff is also made explicit, which the schema leaves implicit.

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 ('Creates a product') plus both accepted input modes (one or more photos, or a product page link) and the analysis produced. This clearly separates it from edit_product, which implies an existing product, and from list_products.

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 concrete workflow routing: the returned product id feeds answer_facts and plan_image_set, and on ok=false the agent is told to explain the problem and offer better photos before planning. It also flags the tool as free, which matters given siblings like buy_credits and estimate_cost. It does not explicitly exclude or compare against edit_product for products that already exist.

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