update_invoice_line

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It adds the useful limitation that only draft invoices can be modified, but it does not mention other potential behaviors such as permission requirements, side effects on totals, or error handling. This is a minimal but non-trivial disclosure.

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, efficient sentence that immediately states the verb, object, and key constraint. There is no wasted wording, and the most critical information (draft-only) is included without elaboration.

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 low complexity of this tool (simple line update with fully described params), the description is largely complete. It includes the essential draft-only restriction and the purpose. It lacks details about return values or error behavior, but for a straightforward update tool with well-documented schema, it covers the main context adequately.

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 describes all 7 parameters with 100% coverage, and the description adds no additional parameter-level meaning. Since the schema already provides the definitions, the baseline of 3 is appropriate; the description does not need to compensate for missing schema information.

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 'Modifier une ligne existante d'une facture' (modify an existing invoice line), which is a specific verb and resource. It distinguishes itself from siblings like add_invoice_line and delete_invoice_line by specifying modification of an existing line, and adds the scope 'draft only'.

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 includes the constraint 'brouillon seulement' (draft only), which tells the agent when this tool is applicable and implicitly excludes non-draft invoices. However, it does not explicitly name alternative tools like add_invoice_line for adding lines, so it provides clear context but no exclusions beyond the draft restriction.

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