cork_get_invoice_line_items

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

With no annotations provided, the description carries the full behavioral burden and does so excellently. It discloses that only nonzero-billed items are returned, that discount items appear as negative totals, and that sub-items are nested with total_billed always 0. These are exactly the surprising behaviors an agent needs to know before invoking the tool.

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?

Three focused sentences, each adding distinct value: primary purpose, filtering/negative-total behavior, and nesting/zero-total behavior. The most important information is front-loaded and there is no filler.

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?

For an input schema that already documents all parameters, the description provides rich semantic context about output composition and edge cases. However, since there is no output schema, the description does not enumerate the other likely line-item fields beyond total_billed and children, which leaves a minor completeness gap.

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 100%, so the baseline is 3. The description confirms the invoice_uuid source but this is already stated in the schema; it adds no new parameter-level detail about page or page_size behavior beyond what the schema provides.

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 states a clear verb+resource pair ('List billed, top-level line items for an invoice') and immediately ties it to the sibling cork_get_invoices, which prevents confusion with the parent invoice tool. It also adds decisive scope details: nonzero totals, discount line items, and nested sub-items.

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 clearly establishes when this tool is relevant: after obtaining an invoice via cork_get_invoices, to inspect its billed line items. It does not explicitly enumerate exclusions or alternatives, but the context is strong enough that an agent can infer the right call path.

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