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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real value beyond that by disclosing the shape of the payload (description, properties, colours, sizes, net/gross price, EAN, per-variant stock, decoration minimums and production time), which matters because no output schema exists.

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?

A single front-loaded sentence that leads with the action and then enumerates payload contents without filler. The enumeration is long but earns its place given the absence of an output schema.

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 must carry return-value information, and it does so reasonably thoroughly. The main gap is the absence of any usage framing linking it to search_products for obtaining the identifier.

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%, with clear per-parameter docs including the colour filter example, the slug pattern, and the language enum default, so the baseline of 3 applies. The description adds no parameter-level meaning of its own, notably omitting that the colour parameter narrows the variant list.

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 ('Returns the details of one product') and enumerates the returned data domains, so the agent immediately knows this is a single-item detail lookup. It does not explicitly contrast itself with the sibling search_products, though 'one product' versus a search implies the distinction.

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?

There is no guidance on when to call this versus search_products or how to obtain a valid product identifier; the only pointer ('slug or id as returned by search_products') lives in the schema, not the description. No prerequisites or exclusions are stated.

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