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

With no annotations provided, the description carries the full behavioral burden. It explicitly discloses read-only behavior, no api_key requirement, stock filtering, return-field limitations, and sort order. This is strong coverage for a simple read-only list tool.

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?

The core English explanation is front-loaded and information-dense, with clear usage signposts. The repeated Vietnamese sentence adds bilingual accessibility but duplicates the English wording, so it is slightly redundant.

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?

Despite no output schema, the description names the exact return fields. Parameter docs are complete in the schema, usage alternatives are explicit, and no missing prerequisite or context is needed for an agent to invoke this tool 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?

Schema coverage is 100%, so the baseline is 3; the description adds value by explaining that category_id comes from list_categories and by framing keyword/category as optional scoping mechanisms. It does not merely repeat schema text.

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 uses a specific verb ('List'), identifies the exact resource ('best-selling in-stock public products'), states the ordering ('most sold first'), and constrains the response to 'public fields only (price VND + units sold)'. This clearly differentiates it from sibling listing and search tools.

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 provides explicit 'WHEN TO USE' guidance ('popular / hot / most bought') and a 'PREFER INSTEAD' section that names four sibling tools with their selecting contexts: latest_products, search_products, recommend_products, and list_category_products. No inference is required.

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