get_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 of behavioral disclosure. It only states that a single invoice and its line items are returned, without mentioning failure behavior, not-found responses, authorization, or response structure. This is too sparse for a tool with zero annotation coverage.

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 extremely concise and front-loaded, with every word contributing. Its brevity is appropriate for a simple single-resource getter, though it may be too terse to serve as a complete standalone explanation.

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?

With no annotations and no output schema, the description is the only source of behavioral context. It covers the basic return object but omits surrounding context such as how to handle unknown IDs, relationship to list_invoices, and any expected response details. For such a low-complexity tool this is borderline viable, but it remains under-specified.

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 schema has 100% description coverage for the only parameter, invoiceid, and the description does not need to add much. The text does not enrich parameter meaning beyond the schema, but the schema already documents the parameter sufficiently.

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 identifies the resource (invoice) and scope ('one invoice') and adds the useful detail that line items are included. It lacks an explicit verb, but the tool name 'get_invoice' supplies the action. It distinguishes from list_invoices by emphasizing a single invoice, though not explicitly.

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 gives no guidance on when to use this tool versus alternatives such as list_invoices. An agent must infer that get_invoice is for a single invoice by ID while list_invoices is for multiple invoices. No exclusions, preconditions, or alternative routing are mentioned.

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