List books

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

Beyond the readOnlyHint annotation, the description discloses several behavioral traits: page size is server-side, pagination uses nextOffset, and the discover view is random and not paginated. These details are not inferable from the schema or annotations, adding significant value.

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 three sentences with no excess. The first sentence front-loads the main purpose and enumerates views, the second explains pagination, and the third clarifies a special case (discover). Every sentence earns its place.

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?

Given the absence of an output schema, the description provides enough context for a list operation: views, pagination mechanism, and a special exception. It could be improved by mentioning the expected structure of returned book data, but for a domain-specific tool it is largely sufficient.

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?

Although the input schema has 100% coverage with descriptions, the description enriches parameter meaning by explaining what each view represents (e.g., 'recently added, default'), restricting the letter parameter to the 'all' view, and clarifying that discover is unpaginated. This goes beyond the schema alone.

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 'Lists books from one of the Calibre-Web views', specifying the resource (books) and action (list) with concrete examples (new, hot, rated, etc.). This differentiates it from siblings like search_books (search) and list_shelves (different resource).

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 explains the different views and pagination behavior but does not provide explicit guidance on when to use this tool versus alternatives such as search_books. It lacks when-not or comparative context, leaving the agent to infer usage based on view names alone.

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