Search Rakuten Books (CDs / Music)

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

Annotations already declare the tool as read-only, idempotent, and open-world. Description adds that it returns specific details (artist, label, JAN, etc.), but does not disclose additional behavioral traits like rate limits or authentication requirements.

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?

Description is concise and front-loaded with English, followed by Japanese translation. No unnecessary information, though bilingual might be redundant for some agents.

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 simplicity and strong annotations, the description covers the main functionality and return values. It lacks details on pagination behavior or error handling, but these are less critical for a search tool with no output schema.

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 covers 100% of parameters with descriptions. The description merely lists fields without adding extra meaning beyond what the schema already provides, so baseline 3 applies.

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?

Clearly states it searches for music CDs with specific fields (title, artist, label, JAN) and returns details. Tool name and sibling list further differentiate from other media searches (e.g., books, DVDs), but no explicit differentiation in description.

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?

Implies usage for CD searches by specific criteria, but provides no explicit guidance on when to use this tool over siblings (e.g., for JAN searches that might also apply to books). No when-not-to-use or alternatives listed.

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