books_update_invoice

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

No annotations are provided, so the description carries the full burden. It only states the update action without disclosing behavioral traits such as partial vs full update, validation rules, or impacts on payments. The phrase 'existing invoice' implies the invoice must already exist, which is minimal 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 short sentence with no fluff, but it is under-specified for a tool of this complexity. It is concise but lacks necessary detail, so it doesn't fully earn 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 21 parameters, no annotations, and no output schema, the description is extremely incomplete. It provides no information about return values, error conditions, or whether all fields are updatable, making it inadequate for reliable tool invocation.

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 0%, and the description does not mention any parameter. With 21 parameters, the agent receives no additional semantics beyond the schema field names, which is insufficient.

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's function: updating an existing invoice. It uses a specific verb ('update') and resource ('invoice'), and distinguishes itself from sibling tools like books_create_invoice or books_delete_invoice.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., invoice must exist) or differentiate from books_create_invoice or books_get_invoice.

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