Get sales invoice

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

With no annotations provided, the description carries the full burden. It notes that the response includes invoice lines, which is a behavioral detail. It also discloses the two identifier options. It doesn't mention error handling or permissions, but for a simple GET operation this is sufficient.

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, front-loaded sentence with no filler words. It conveys the core purpose, the identifier options, and the inclusion of lines efficiently.

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 tool's simplicity, the description is complete: it identifies the target resource, how to select it, and what is included in the result. It lacks an explicit fallback for the case where neither id nor invoice_number is provided, but the phrase 'by invoice number or GUID id' implies a requirement to provide one.

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 already documents all three parameters with descriptions (100% coverage). The description adds minimal new meaning beyond the schema—it restates that lookup can be by invoice number or GUID id, and that lines are included, which slightly reinforces the include_lines parameter.

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 target resource ('one sales invoice'), and the scope ('by invoice number or GUID id, including its lines'). This distinguishes it from list-like siblings such as bc_list_sales_invoices.

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 when to use this tool: when you have a specific invoice number or GUID id and need a single invoice with its lines. It does not explicitly contrast with alternative tools (e.g., list all sales invoices), but the context of siblings makes the distinction clear.

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