get_book

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

With no annotations, the description carries full responsibility. It clearly indicates a read operation ('Fetch') and implies non-destructive behavior, but it doesn't disclose behaviors like not-found handling, error conditions, or any authentication requirements. The 'same shape' note is helpful but minimal.

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 a single sentence with zero filler. It front-loads the core action and parameter, and the 'same shape' note is efficient. Every word serves a purpose.

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 an output schema, so return values are covered. For a simple get-by-ID tool, the description provides enough to call it correctly if you know book_id, but it omits explicit guidance on when to prefer this over list_books or search_books, and lacks any prerequisite information (e.g., how to obtain a valid book_id). It's sufficient but not comprehensive.

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 coverage is 0%, so the description must compensate. It names book_id as the lookup key and implies it comes from list_books (via 'same shape list_books returns'), but it doesn't elaborate on its format, provenance, or any constraints beyond the schema's type string. This is adequate but not enriching.

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 states a specific verb ('Fetch'), a resource ('catalog record'), and the key parameter ('by book_id'). It also notes the return shape matches list_books, which differentiates it from siblings like get_book_text (text) and search_books (multiple results). This is unambiguous.

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 implies usage when you have a book_id and need a single catalog record, and the 'same shape list_books returns' hint suggests you might already have the data from list_books. However, it doesn't explicitly state when not to use it or name alternatives, so it lacks explicit exclusions.

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