xero_invoices_get

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

With no annotations, the description carries the full burden. It transparently states what the tool returns ('full invoice details including line items, amounts, and payment status') and implies a read-only side-effect-free behavior via the verb 'Get'. It does not cover errors or auth, but for a simple lookup 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 sentence with a front-loaded verb and resource, followed by a concise statement of return value. Every word earns its place 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?

Given the tool's simplicity (one required parameter, no output schema), the description fully covers what the tool does and what information it returns. It is complete enough for an agent to select and invoke it correctly without additional context.

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 single parameter invoiceId is described in the schema. The description adds minimal semantic value by linking the ID to 'a specific invoice' and mentioning detailed output, but it does not go beyond the schema's existing meaning.

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 uses the specific verb 'Get' and clearly identifies the resource: 'a specific invoice by its ID'. It distinguishes this tool from sibling tools like xero_invoices_list (list all invoices) and xero_invoices_create/update_status by focusing on fetching detailed data for a single 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?

The description provides clear context: use this tool when you have an invoice ID and need full details. It implies the contrast with listing or creating invoices, though it does not explicitly name alternative tools or exclusions. This meets the 'clear context, no exclusions' bar.

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