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

Annotations already cover the safety profile (readOnlyHint, openWorldHint). The description adds genuinely useful behavior: nonsense keywords return a real empty set rather than a fallback, and pagination is 'real' rather than capped. It doesn't mention rate limits or auth, but for a read-only search that is minor.

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?

Three tight sentences, front-loaded with the verb and resource, followed by return contents and the differentiator. Dense but no wasted clauses; the return-content enumeration is slightly long but informative.

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, return fields are covered by the schema, and the description still summarizes them and clarifies pagination and no-fallback behavior. Nothing an agent needs to call this correctly is missing.

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%, so page and page_size are already documented with ranges and defaults. The description adds only that pagination is page-based, which the schema implies anyway. Baseline 3 is appropriate.

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?

Specific verb (search) plus resource (H&M product listings) and scope (free-text keyword), and it explicitly distinguishes itself from category browsing, the nearest sibling (hm_categories). An agent can route between them without opening schemas.

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?

States the usage context (free-text keyword lookups) and names an alternative mode (category browsing) with the condition that selects it. It stops short of an explicit 'don't use this for X' exclusion, but the context is clear.

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