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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description still earns credit for two genuinely useful behaviors beyond the annotations: stock is live, and products without options return a single synthetic variant with id "default".

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?

The purpose sentence is front-loaded and the synthetic-variant note is high-value, but the trailing Args block is pure filler that duplicates structured schema fields. The description is not bloated overall, but one of its three sections earns nothing.

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 an output schema present and annotations covering the read-only/idempotent profile, return values and safety need not be explained, and the synthetic-variant edge case is covered. The remaining gap is the absence of any real parameter semantics for a 2-param tool, leaving the definition merely adequate.

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 0%, so the description carries the full burden, yet its Args block only restates each parameter name as 'The project ID' / 'The product ID'. That is tautological and adds no format, source, or constraint information an agent could not already infer from the schema titles.

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 ('List a product's options and variants') and adds scope ('with live stock'), which clearly separates it from list_commerce_products and get_commerce_product. It does not explicitly name a sibling, so it stays just short of 5.

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?

Usage is implied: call this to enumerate variants for a given product. There is no explicit when-to-use versus when-not-to-use guidance and no routing to alternatives such as get_commerce_product, so it is only minimally viable.

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