book_lists

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral detail beyond annotations: results are paginated in batches, the limit is capped at 100, and the ordering is by popularity. These are not inferable from the annotations or schema, making the description genuinely informative.

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 compact and front-loaded. The first sentence states the core purpose and ordering, followed by a sentence on output fields and use cases, then a final sentence on pagination and cap. Each sentence earns its place—no fluff or redundancy—and the structure allows an agent to quickly grasp what the tool does and its constraints.

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 list tool with two parameters and an existing output schema, the description is thorough. It covers the result fields (title, votes, book count, URL), the use case, the pagination behavior, and the cap. It does not need to explain return formats because the output schema handles that, and the annotations already cover safety, so nothing critical 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?

The input schema has 0% description coverage, placing the burden on the description. While the description implicitly references book_id (the book in question) and mentions that 'limit is capped at 100,' it does not explicitly explain that limit controls the number of lists returned per batch, nor does it mention the default value of 10. This is partial compensation but not complete.

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 explicitly states the verb ('List'), the resource ('the Listopia lists a book appears on'), and the ordering ('by popularity'), with an example. This clearly distinguishes it from siblings like get_book (which fetches a single book) and similar_books (which suggest related works) without needing to open schemas.

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?

It provides clear context on when to use the tool ('Good for "what kind of book is this / what's it grouped with" and for discovery'), which guides an agent toward appropriate scenarios. It does not explicitly name alternatives or state when not to use it, but the purpose is specific enough to avoid confusion with most siblings.

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