update_invoice_line_item

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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It only says 'update', but does not specify whether updates are partial (PATCH-like), whether unspecified fields are preserved, what side effects may occur (e.g., recalculating invoice totals), or any permission requirements. This is a significant gap for a mutation 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?

The description is a single, concise sentence with no fluff. However, it is extremely minimal and adds little value over the tool name itself, making it borderline under-specified. It is not as informative as the 'update_drive' example which listed specific fields.

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?

With no annotations, no output schema, and a 6-parameter tool, the description provides insufficient context. It lacks usage guidance, behavioral details, and any note about effects on the invoice or return values. The schema helps with parameters but the description alone does not make the tool fully comprehensible for an agent.

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 input schema has 100% description coverage for all 6 parameters, each with clear descriptions. The tool description adds no parameter information beyond what the schema already provides. According to the baseline rule, this scores 3.

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 specific action ('Update') and the target resource ('a line item on an invoice'). It distinguishes from sibling tools by explicitly naming the resource as a line item, differentiating it from add/delete line item and update invoice tools.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention that this is for modifying existing line items or that it should be used instead of adding or deleting. The verb 'update' implies usage, but no explicit context or exclusions are provided.

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