update_invoice

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

Discloses that only provided fields change and that published invoices cannot be updated. However, no annotations are present, and the description does not specify prerequisites (e.g., invoice must be in draft status), potential side effects, or permission requirements.

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?

Two concise sentences with no wasted words. Essential information (action, resource, constraints) is front-loaded and clear.

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 9-parameter update tool with no output schema and no annotations, the description covers core behavior and a key constraint. It could mention that the invoice must be a draft, but overall it is fairly complete.

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 coverage is 100% with clear parameter descriptions. The tool description does not add additional parameter semantics beyond what the schema already provides, meeting the baseline.

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?

Description clearly states verb 'Update', resource 'existing draft invoice', and distinguishes from siblings like create_invoice and publish_invoice by specifying the draft-only constraint and field-level update behavior.

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?

Explicitly says when to use (update draft invoices) and when not (cannot update published invoices). While alternatives like publish_invoice are implied by context, the description does not explicitly mention them, leaving some room for improvement.

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