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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds only that the response includes variant information alongside the product; it says nothing about behavior when no match exists (error vs. empty result).

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 short front-loaded sentences with no filler. The trailing REST path ('GET /products/search/barcode/{barcode}/.') is implementation noise rather than agent-relevant guidance.

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?

For a single-parameter lookup with no output schema this is minimum viable: it names the resource and mentions variants, but omits the not-found behavior and any sense of the returned payload shape, which an agent needs to handle misses correctly.

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?

One required parameter with 100% schema description coverage; the schema already documents 'Product barcode.' The description adds no format, length, or encoding guidance (relevant for a barcode string with maxLength 100), so baseline 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?

States a specific verb and resource ('Find the product (and variant) with this barcode') and the identifier type (barcode) implicitly separates it from hiboutik_get_product (id-based) and hiboutik_search_products_by_name. It doesn't explicitly name those siblings, so the differentiation is inferred rather than stated.

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 by the barcode-specific phrasing – an agent with a barcode rather than an id or name will pick this. There is no explicit when-to-use/when-not statement nor a pointer to hiboutik_get_product or hiboutik_search_products as alternatives.

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