rakuten-mcp

Browse Rakuten Kobo Genres

kobo_genre_search

Read-onlyIdempotent

Browse the Kobo eBook genre hierarchy. Start at top-level '101' and drill down with child genre IDs to narrow search results.

Instructions

Browse the Rakuten Kobo eBook genre hierarchy. Top-level is '101' (電子書籍). Pass a child genre ID returned by this tool to drill down. Returns the current genre, its ancestors, and its direct children — useful for narrowing kobo_ebook_search results.

[JA] 楽天Koboのジャンル階層を参照します。最上位は '101'(電子書籍)。子IDを渡して掘り下げ可能。現在のジャンル、祖先、子ジャンルを返します。kobo_ebook_search の絞り込みに利用してください。

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "kobo_genre_search"
  }
}

Input Schema

Name	Required	Description	Default
`koboGenreId`	No	Kobo genre ID. Top-level is '101' (電子書籍). Drill down with returned child IDs. ジャンルID。トップは '101'(電子書籍)。子IDで掘り下げ。	101

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.1.0Jun 19, 2026

TDQS

A4.1/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the tool is known to be safe and idempotent. The description adds context about the return structure (current genre, ancestors, children) but does not disclose additional behavioral traits beyond that. 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.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise with two sentences in both English and Japanese. It is front-loaded, every sentence adds value, and there is no unnecessary information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (one parameter, optional, no output schema), the description fully covers purpose, usage, and output structure. It mentions the hierarchical nature and linkage to kobo_ebook_search, providing sufficient context for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema description coverage is 100%, and the description largely repeats the schema's explanation of the koboGenreId parameter. It adds marginal value ('Pass a child genre ID...'), so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it browses the Rakuten Kobo eBook genre hierarchy, specifies the top-level ID '101', and indicates it returns current genre, ancestors, and children. It also distinguishes from sibling genre search tools by emphasizing the Kobo domain.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains how to drill down by passing child IDs and links to kobo_ebook_search. However, it does not explicitly exclude use cases or contrast with sibling genre tools like books_genre_search or ichiba_genre_search.

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