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

Annotations only cover readOnly/openWorld. The description adds genuinely useful behavior beyond them: which recommendation lists appear varies by product, and an unrecognized product_id returns a well-formed empty result rather than an error. This error-tolerance disclosure is high-value for an agent deciding whether to trust the response.

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, front-loaded with the core purpose, followed by the useful caveats. The parenthetical explaining list variability is somewhat long but earns its place. No redundant filler.

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 annotations carrying the safety profile and an output schema handling the return shape, the description focuses on the right things: purpose and the non-obvious variability/empty-result behavior. The only real gap is product_id format, which is left to inference.

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 0% for the single product_id parameter, so the schema explains nothing. The description tells the agent that unrecognized ids are tolerated, which adds meaning about valid input, but never specifies the expected id format or where to obtain it. Partial compensation only.

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+resource: retrieving H&M's own product-detail recommendation lists for one product. The phrase 'H&M's own' scopes it to the brand, distinguishing it from hm_product or recommendation tools from other brands. It never explicitly names a sibling alternative, but the purpose is unmistakable.

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 (you call it to get recommendation lists for a product you already have an id for), but there is no explicit when-to-use/when-not statement and no named alternative (e.g., hm_product for full detail). The note about which lists appear is behavioral, not routing guidance.

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