Get Rakuten Ichiba Bestseller Ranking

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

Annotations already indicate readOnlyHint, openWorldHint, idempotentHint. The description adds significant context: states the tool returns specific fields (rank, price, review stats, etc.), gives detailed shipping analysis steps (shippingVerified handling, web-search for shipping costs, never guess shipping), and notes Rakuten's ranking cap of ~1000 items. No contradiction with annotations.

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 relatively long but well-structured: main purpose first, then usage guidance, then detailed protocol steps in numbered format. Japanese version follows efficiently. Slightly verbose due to duplication of steps in both languages, but necessary for bilingual audience. Front-loaded key 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?

Given the tool's complexity (5 optional params, no output schema), the description is highly complete. It covers purpose, filtering options, returned fields, usage protocols, and shipping analysis steps. The absence of an output schema is compensated by listing returned data fields. All essential information for correct agent invocation is present.

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% and each parameter already has a description. The tool description adds extra value by explaining usage constraints (page max 34 due to Rakuten cap, genre_id default 0 for overall) and contextual hints (age demographic filtering), going beyond the schema. Deduction for not elaborating on all parameters, but adequate given high schema coverage.

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 retrieves Rakuten Ichiba bestseller rankings, supports filtering by genre, period, age, and gender, and lists returned fields. It distinguishes from sibling tools like ichiba_genre_search by mentioning genre ID lookup, and includes both English and Japanese for clarity.

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?

Explicitly tells when to use the tool vs alternatives: directs to ichiba_genre_search for genre IDs, and recommends the compare_ichiba_value prompt for cost comparisons. Provides a numbered step-by-step protocol for direct use, including pre-sorting and shipping handling rules.

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