compare_prices商品名・型番を指定して楽天市場内で最安値を比較します。送料・ポイント還元込みの実質価格で順位付けして返します。
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | 商品名・型番・キーワード（例: 「Anker PowerCore 10000」「iPhone15 ケース」） | |
| spu_rate | No | 楽天ポイントSPU倍率（デフォルト5） | |
| max_price | No | 上限価格（円） | |
| max_results | No | 表示件数（最大10件、デフォルト5件） |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, and the description adds meaningful behavioral context: it ranks results by effective price including shipping and point rebates. This goes beyond the annotation and helps the agent understand how results are ordered. No contradictions.
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 a single, concise sentence that front-loads the core purpose and includes the key ranking behavior. Every word earns its place, with no redundant information.
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 straightforward read-only price comparison tool, the description covers purpose and output ranking logic. However, since there is no output schema, it doesn't specify the exact return structure or error behavior. This is a minor gap, but the tool is simple enough that the description is mostly complete.
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?
The input schema has 100% coverage with all parameter descriptions. The description adds no additional parameter semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.
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 tool compares lowest prices on Rakuten Market by product name/model number, with a specific verb (比較) and resource (楽天市場). This distinguishes it from sibling tools like recommend_for_consumer and search_business_hotel.
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 description provides clear context: use when you need to find the cheapest price for a specific product on Rakuten. It does not explicitly mention alternatives or when-not-to-use, but the sibling tools are clearly different in purpose, so the usage context is unambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct task: price comparison for a specific item, product recommendation by keyword and budget, and hotel search with location and dates. No overlap.
All tools use consistent snake_case and verb_noun pattern (compare_prices, recommend_for_consumer, search_business_hotel).
Three tools is on the low side but covers the core functions of comparing prices, recommending products, and searching hotels. Reasonable for a focused utility server.
The tool surface covers basic search and comparison but lacks operations like managing favorites, booking hotels, or viewing detailed product info. Some gaps exist for a full shopping/travel assistant.