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

Annotations only declare readOnlyHint=true, so the description carries the burden of disclosure and does well: it names the returned sub-resources and clarifies the entity is a variant, not a parent product. It also gives the underlying endpoint GET /products/{product_id}, which helps an agent reason about failure modes. Missing error behavior (e.g. 404 on unknown id) keeps it from a 5.

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 sentences, zero padding, with the payload description and endpoint front-loaded. Every clause (variant distinction, returned fields, endpoint) carries 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?

With no output schema, the description's enumeration of returned fields (prices, codes, suppliers, outlet taxes) is what tells the agent whether it needs a follow-up call. For a 2-parameter read tool with full schema coverage, that is nearly sufficient; only the `includes` expansion behavior and error semantics remain undescribed.

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 100%, and the `includes` parameter comes with a substantive caveat about 'families' being required alongside brands/categories/etc., so the schema does the heavy lifting. The description adds no meaning beyond 'by id' and never mentions that related records are opt-in via includes.

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 ('One product (variant) by id') and lists the payload contents (prices, codes, suppliers, outlet taxes), which is more precise than the title 'Get product'. It implicitly separates itself from list_products/search_products by being a single-record fetch, but never names those siblings.

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 only implied: 'by id' signals you must already have an identifier, and the schema note '(from list_products)' hints at the discovery path. There is no explicit guidance on when to prefer this over search_products or list_products, and no exclusion criteria.

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