get_book_metadata

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

No annotations are provided, but the description discloses the cost ($0.002), payment method (x402, USDC on Base), wallet requirement, and lists the return fields. This is substantial context for a read-only metadata operation, though it omits error handling behavior.

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?

Two concise sentences: the first defines the tool's scope and outputs, the second provides prerequisite and cost. Every sentence carries meaningful information with no redundancy.

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 single-parameter tool with no output schema, the description covers inputs, outputs, prerequisite (search_books first), and cost/payment details. It is sufficient for an agent to select and invoke the tool correctly, though it does not specify the exact return format.

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 100% and the schema already describes book_id as 'Gutenberg book id, from search_books.' The description adds 'indexed book' and integer context but does not materially improve parameter understanding beyond 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?

Description states 'Full metadata for one indexed book by book_id' and enumerates specific fields (title, author, year, subjects, etc.), making its purpose unmistakable and distinguishing it from siblings like get_chapter and search_books.

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?

Provides explicit prerequisite: 'Use search_books first to find a book_id.' Also adds cost and wallet requirements, giving clear context for when it should be invoked. It does not explicitly name alternatives to avoid, but the coverage is strong.

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