apple_books_book

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

With no annotations provided, the description carries the burden of disclosing behavior. It adds value by specifying the source ('public catalog page') and the normalized fields returned (ISBN, page count, publisher, audience, rating histogram, series linkage). However, it does not explicitly state that this is a read-only operation, nor does it mention rate limits, authentication, or error behavior, leaving some gaps for a no-annotation tool.

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 highly concise: two sentences that front-load the action and resource, followed by a list of key metadata fields. Every word contributes to understanding, with no redundant or filler content.

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 retrieval tool, the description is complete: it states the purpose, the source, and the kind of data returned. The schema documents the parameters, and the description enumerates key output fields even in the absence of an output schema. It does not detail response structure or how to obtain the ID, but that is not essential for basic use.

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 input schema covers all three parameters (id, lang, country) with descriptions, achieving 100% coverage. The tool description does not add any additional meaning to these parameters beyond what the schema already provides, 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.

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

The description clearly states the tool retrieves Apple Books book details, using the specific verb 'Retrieve' and resource 'Apple Books book details'. It distinguishes from sibling tools like apple_books_audiobook, apple_books_book_reviews, and apple_books_book_similar by focusing on the book's metadata, making the purpose unambiguous.

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 implies the tool is for retrieving book metadata from a public catalog page, which provides context for when to use it. However, it does not explicitly mention when not to use it or name alternatives (e.g., 'for reviews, use apple_books_book_reviews'), so guidance is implied rather than explicit.

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