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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), so the description adds value by disclosing the response shape and the conditional nature of reviews ('when the product has any'). It does not mention rate limits or failure modes, but the content disclosure is genuinely useful.

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?

Purpose is front-loaded, then the distinguishing clause, then the parameter note. It is a dense single sentence plus one short follow-up; every clause carries information, though it is slightly heavy to parse.

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 the return format needn't be spelled out, yet the description still characterizes the payload helpfully. Safety is covered by annotations and the single parameter is explained, leaving little an agent needs that 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 coverage is 0%, so the description carries the burden and does: it explains product_id is the numeric id taken from a listing/search result's id field, telling the agent exactly where to source the value. That meaning is not in the schema, which only declares a string.

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?

The description states a precise verb and resource (one H&M product's full detail) and enumerates the payload: colors with per-size price and availability, aggregate rating, reviews with fit-feedback tags. It explicitly distinguishes itself from hm_listing and hm_search, so an agent can tell the three apart without opening a 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?

It names the alternatives (hm_listing, hm_search) and states what they lack, which routes the agent here when full product detail is needed. It stops short of an explicit 'use this when'/'do not use when' formulation, but the exclusion clause is clear guidance.

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