Retrieve Apple Books book details and metadata by numeric ID, including ISBN, page count, publisher, audience, rating histogram, and series linkage.
Retrieve Apple Books book details. Returns book metadata from Apple Books, including ISBN, page count, publisher, audience, rating histogram, and series linkage.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Apple Books numeric book ID | |
| lang | No | Result language tag | |
| country | No | Two-letter storefront country code |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does disclose the returned fields (ISBN, page count, publisher, audience, rating histogram, series linkage), which is useful behavioral context for a read tool, but says nothing about auth needs, rate limits, or that the id must be a numeric Apple Books ID.
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?
Two sentences, front-loaded with the action and followed by the return contents. No filler, though the field enumeration in the second sentence is a fairly long list.
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?
With no output schema, the description compensates by listing the key return fields, and all three params are documented in the schema. For a simple read-only retrieval tool this is largely complete, missing only usage routing and prerequisite notes.
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 100%, so the schema already documents id, lang, and country. The description adds no syntax, format, or default details beyond what the schema provides, so the 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?
States a specific verb+resource ('Retrieve Apple Books book details') and enumerates the returned metadata, making the single-book retrieval intent clear. However, it does not distinguish itself from close siblings like apple_books_search or apple_books_book_similar, which an agent might confuse it with.
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 when-to-use guidance, no mention of alternatives (e.g. apple_books_search for discovery vs this for a known ID), and no statement of prerequisites. The agent must infer usage entirely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.