List all books

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds useful behavior beyond that, disclosing the exact row format and the pagination footer that names the next offset. It stops short of stating auth needs or ordering guarantees, but adds real value over the annotations.

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?

Front-loaded with the core action, followed by output shape, the alternative tool, then args. Three compact blocks with no filler sentences.

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?

No output schema exists, yet the description supplies the return format and paging semantics, and parameters are fully specified. Nothing an agent needs to call this correctly is missing.

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%, so the description must carry the parameter burden and does: limit is bounded (1–500, default 200) and offset is explained as paging with a footer naming the next offset when more results exist. This is meaning well beyond the bare integer properties in the schema.

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 and resource ('List all books in my Apple Books library') and the scope word 'all' implicitly separates it from filtered siblings such as search_books, get_books_by_genre, and get_books_in_progress. The one-line output format ('[id] title by author') further pins down what this tool returns.

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?

Explicitly routes the agent onward: 'Use describe_book(id) for details on any book.' However, it never states when to prefer this over search_books or get_collection_books, so it gives a clear follow-up path but no exclusions among the many list/search siblings.

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