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

No annotations are provided, so the description carries the behavioral burden. It usefully discloses cost ('FREE') and result cap ('top 3'), but does not state read-only nature, permissions, rate limits, or return format.

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?

Extremely concise and front-loaded: cost first, then action, resource, scope, and result limit. Every element adds useful information with no filler.

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 simple one-parameter search this covers selection and invocation basics, including free access and a top-3 result cap. However, with no output schema or annotations, it leaves return shape and sibling-tool distinctions under-specified.

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 description coverage is 0% for the single required title parameter, so the description must compensate. 'by title keyword' clarifies that matching is keyword-based rather than exact, but gives no format or matching-detail guidance.

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?

States a specific verb ('Search') and resource ('National Diet Library catalogue'), plus title-keyword scope and a top-3 limit. It does not mention the siblings creator_search or library_search_pro, so an agent cannot fully distinguish this tool from them from the description alone.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no alternatives are named. 'FREE' and 'top 3' imply a basic quick search, but the agent must infer that library_search_pro is for broader or advanced searches.

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