search_books

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It discloses the return format (list of matching records with title, author, isbn, available_copies), the empty-result behavior (plain string message), and the match semantics (case-insensitive, partial). This is thorough for a read-only search 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?

Three well-organized sentences, zero filler. Opening sentence states the core purpose, second sentence covers usage guidance, third sentence covers return behavior. Each line earns its place and front-loads the most important information.

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?

The tool has a single simple parameter, an output schema that documents the return structure, and the description covers behavioral details like empty results and matching rules. For a search tool of this complexity, the description is complete and there are no gaps.

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 single 'query' parameter is already documented in the schema ('matched against each book's title and author fields'). The description adds marginal behavioral context (case-insensitive, partial) but doesn't add significant new semantic detail beyond what the schema covers.

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?

Clear specific verb+resource: 'Search the library catalog by title or author'. Clearly states case-insensitive and partial-match behavior, and specifically enumerates what fields are searched. Distinguishes itself from siblings (return_book, borrow_book, check_availability) by being the search/discovery tool.

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 states when to use: 'whenever the user wants to find books, browse what's available on a topic, or look up a specific author/title but doesn't already know the ISBN.' The ISBN exclusion phrase clearly draws the boundary against catalog-lookup alternatives, which is helpful guidance.

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