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

With no annotations, the description carries the full burden and does so well: it discloses the in-stock/public scope, same-category prioritization, best-selling order, fallback to newest products from other categories, and the limitation to public fields (VND price + sold count). This is rich behavioral context beyond what schema or annotations would provide.

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 behavior is front-loaded in English, and the Vietnamese restatement adds a clear usage note. The bilingual repetition creates some redundancy, preventing a perfect score, but there is no filler beyond that.

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 simple two-parameter list tool with no output schema, the description covers the selection logic, ordering, fallback behavior, and the public fields returned. It could enumerate the exact response fields more explicitly, but the current level is sufficient for an agent to invoke the 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 description coverage is 100%, so the schema already documents the id integer and limit default/max. The description reinforces id as the anchor but adds no new parameter-specific syntax or format details beyond the schema.

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 specific verb and resource ('Given a product id, list similar in-stock public products') with concrete behavioral details like same-category and best-selling order. It does not explicitly contrast itself with sibling tools such as recommend_products or search_products, but its unique scope is clear enough to identify its purpose.

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?

The Vietnamese clause explicitly defines when to use it: for suggesting replacements or associated purchases, and then possibly comparing with compare_products. It gives clear context but no explicit exclusions or when-not-to-use guidance relative to alternatives.

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