books_get_invoice

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It only states the basic retrieval action without mentioning side effects, required permissions, error behavior, or return format. For a get operation this is minimal but lacks useful context.

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, focused sentence of nine words with no redundant information. Every word contributes to the purpose statement, making it highly concise and well-structured.

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 get-by-ID tool with one parameter and no output schema, the description covers the core action and parameter adequately. It is reasonably complete given the low complexity, though it omits potential error handling and return value details.

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 single parameter 'invoice_id' is only documented as a string in the schema, with 0% schema coverage. The description's 'by ID' clarifies that the parameter is the invoice identifier, adding some meaning, but it does not specify format, length, or how to obtain it.

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 action ('Get'), the resource ('a specific invoice from Books'), and the method ('by ID'). It distinguishes itself from list-style siblings like books_get_invoices by specifying 'specific invoice', though it does not explicitly differentiate from books_get_invoice_pdf.

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?

No guidance is given on when to use this tool versus alternatives. It does not mention using books_get_invoices for listing or books_get_invoice_pdf for PDF retrieval, leaving the agent to infer usage context from the sibling names.

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