approve_invoice

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions 'fails loudly' for version mismatches, but does not disclose other important behaviors such as whether the operation is irreversible, permission requirements, or side effects on the invoice state. The description is insufficient for a state-changing action.

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 very short and front-loaded, conveying the essential purpose and a key usage warning in just two sentences. However, it may be too terse given the lack of behavioral and parameter details, but it earns its place without 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?

Given the presence of an output schema, return values need not be explained, but the description lacks context about the approval workflow, prerequisites (e.g., invoice must be a draft), and effects (e.g., subsequent posting). Among many invoice-related sibling tools, it does not sufficiently differentiate when to use 'approve_invoice' versus 'update_invoice' or 'generate_invoice'. The description is incomplete for a decision-making 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 two required parameters ('invoice_id', 'invoice_number') with no descriptions, and schema description coverage is 0%. The tool description does not provide any additional meaning, format, or context for these parameters, relying solely on their names which may be insufficient for correct usage.

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 explicitly states the action ('Approve a draft invoice for posting'), clearly identifying the verb and resource. It also distinguishes itself from sibling tools like 'create_invoice' or 'update_invoice' by specifying the approval workflow. The additional note about not being in /v1 provides further clarity.

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 warns that the tool is not exposed in /v1 and will fail loudly, providing a clear context for when not to use it. However, it does not explicitly state when to use this tool over alternatives like 'generate_invoice' or 'update_invoice', leaving room for ambiguity about the approval workflow.

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