Update Line Item

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

No annotations are provided, so the description carries the full behavioral burden. It does indicate the tool only works on draft invoices, which is useful context, but it omits whether updates are partial or full, whether unspecified fields remain unchanged, whether the line item must exist, and what happens on failure. For a mutation tool with no annotations, this is a moderate gap.

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?

A single, front-loaded sentence that efficiently conveys the core action and scope. 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?

For a 7-parameter mutation tool with no annotations and no output schema, the description is minimally adequate. It mentions the draft-invoice constraint but lacks details on update semantics, error conditions, and permission requirements. The high schema coverage compensates for parameter documentation, but behavioral context remains thin.

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 schema already documents all parameters in detail. The description lists four updatable fields (description, quantity, unit_price, discount), which repeats what the schema provides and omits unit_id and tax_rate_id. No additional syntax or format details are added beyond the schema.

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 specific verb and resource ('Update an existing line item on a draft invoice') and enumerates the mutable fields. It is clear but does not explicitly distinguish itself from sibling tools like productive_create_line_item or productive_delete_line_item, aside from the implicit verb difference.

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?

Usage is implied by 'existing' and 'draft invoice,' but there is no explicit guidance on when to use this tool versus alternatives such as creating a new line item or updating a non-draft invoice. No exclusions or prerequisites (e.g., required permissions) are given.

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