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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond them: the 10-id ceiling, a detailed inventory of what the response contains (tiered prices in EUR and storefront currency, stock in packages, photos), and the notable caveat that 'Photo facts are observations, not guarantees' — a data-reliability warning no annotation carries.

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 essential facts — verb, limit, id source — are front-loaded, and the long field enumeration earns its space because there is no output schema to describe the return payload. It is a dense single sentence rather than a run-on of redundant claims.

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 correctly compensates by enumerating returned fields, and it discloses the id source, the batch limit and a data-quality caveat. The main remaining gap is undefined edge behavior — whether more than 10 ids errors, truncates, or how unknown ids are reported.

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% and there is only one parameter, whose description already says 'Product ids, at most 10'. The prose merely restates the batch limit, so it adds no syntax or format meaning beyond the schema; the baseline of 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?

Opens with a specific verb and resource ('Full details of up to 10 products by id') plus a hard batch limit, and names where the ids come from ('from search or a category'), which cleanly separates it from the search and categories siblings. An agent can tell it apart from those tools without opening the schema.

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?

The parenthetical 'from search or a category' establishes the prerequisite workflow that produces the ids, so the agent knows this is a follow-up retrieval call rather than an entry point. It does not state exclusions or what to do when a lookup fails, but the usage context itself is unambiguous.

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