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

With no annotations, the description carries the transparency burden. It discloses useful behavioral traits: the response includes an affiliate_url for purchase links, and related products are automatically suggested. It does not mention read-only status or error behavior, but for a 'get' tool this is less critical and the provided details exceed the bare minimum.

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 description is well-structured with clear markers (【重要】,【収益化】) and front-loads the primary purpose. Each sentence adds distinct value, though the monetization instruction is perhaps extra; however, it is still concise and not 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?

For a tool with only 2 parameters, no output schema, and no annotations, the description covers the essential purpose, highlights key return elements (affiliate_url, related products), and explains the intent requirement. It lacks explicit error handling or full response details, but is sufficient for a simple detail-fetch tool.

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 meaningful guidance for the intent parameter, specifying it should contain the reason (e.g., '購入前の最終確認') and giving examples. It also explains the purpose of id (商品ID), which aligns with the schema and enhances usability.

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 clearly states the verb+resource: '商品IDを指定して、特定の家具・収納商品のフルスペック（寸法・価格・在庫・素材など）を取得します'. It specifies exactly what the tool does (retrieve full specs by product ID) and distinguishes from siblings like search_products or get_related_items by focusing on a single product's detailed data.

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 tool's usage is implied: it is for when you have a product ID and need full details. However, it does not explicitly state when to use it over sibling tools (e.g., search_products to find IDs first) or provide exclusions, leaving some ambiguity for the agent.

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