list-invoices

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

With no annotations provided, the description carries full burden and does well by disclosing key behavioral traits: it specifies the invoice statuses included (Draft, Submitted, Paid), describes pagination behavior (10 invoices per page, requires page parameter), and explains how to handle subsequent calls. It doesn't mention rate limits, authentication needs, or error conditions, but provides substantial operational 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 appropriately sized but not optimally structured. The first two sentences establish purpose, but the remaining text mixes usage guidance with implementation details. While all content is valuable, it could be more front-loaded with core functionality before detailed procedural instructions. No wasted sentences, but organization could be improved.

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 no annotations and no output schema, the description provides good context for a listing tool. It covers purpose, scope, filtering options, and pagination behavior. Missing elements include return format details, error handling, and authentication requirements, but for a list operation with clear parameters, it's reasonably complete. The pagination guidance is particularly valuable.

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 only 33% (only 'invoiceNumbers' has a description), but the description compensates somewhat by explaining the purpose of contact and invoice number filtering in the usage guidance. However, it doesn't explain the 'page' parameter's semantics or format, nor does it clarify that 'contactIds' and 'invoiceNumbers' are arrays. The description adds value but doesn't fully compensate for the low schema coverage.

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 purpose: 'List invoices in Xero' with specific scope details ('This includes Draft, Submitted, and Paid invoices'). It distinguishes from siblings like 'create-invoice' or 'update-invoice' by focusing on listing rather than creating/modifying. However, it doesn't explicitly differentiate from other list tools like 'list-credit-notes' or 'list-quotes' beyond the resource type.

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 explicit guidance on when to use this tool: 'Ask the user if they want to see invoices for a specific contact, invoice number, or to see all invoices before running.' It also includes detailed pagination instructions ('Ask the user if they want the next page... If they want the next page, call this tool again...'). This gives clear context for usage decisions.

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