Browse Rakuten Ichiba Genres

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

The description adds behavioral details beyond the annotations: fetching ancestors, siblings, and direct children for a given genre ID. The annotations already indicate read-only, idempotent, and open-world, and the description does not contradict them.

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 two concise English sentences (plus Japanese translation) with no wasted words. It front-loads the purpose and then explains behavior.

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?

The description is complete for a simple read-only browse tool: it explains what the tool does, when to use it, and the parameter behavior. It does not describe the output format, but given the tool's simplicity and lack of output schema, this is acceptable.

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 single parameter genre_id has 100% schema coverage; the description adds the special behavior for value '0' (top-level) and drilling down, which is not explicitly in the schema description but is implied. This adds value 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 clearly states the tool browses the genre hierarchy, specifies the verb (Browse), resource (genre hierarchy), and the effect of passing '0' vs a specific genre ID. It is distinct from sibling tools that search or rank items.

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 explicitly says it is useful for narrowing item searches or discovering categories, providing clear context. It does not give explicit when-not-to-use or alternatives, but the sibling tools are sufficiently different.

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