sign_invoice

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

With no annotations, the description carries full responsibility for disclosing behavioral traits. It mentions 'digital signature' but does not explain the effects (e.g., whether the action is irreversible, requires special permissions, or updates invoice status). The return value is also undisclosed.

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 that is front-loaded with the primary action. It is appropriately sized for a simple tool with one parameter, though it could be slightly more informative without becoming verbose.

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 lack of annotations, no output schema, and the existence of similar sibling tools, the description is too minimal. It does not explain the tool's role in the invoice lifecycle relative to accept_invoice/reject_invoice, nor does it describe side effects or success/failure indicators. This leaves critical context missing for an agent to select and invoke it correctly.

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 parameter 'invoice_id' is already documented in the schema. The description adds no additional semantic detail beyond what the schema provides, earning the baseline score of 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 action ('Sign') and the resource ('an invoice'), specifying 'with digital signature' for precision. However, it does not explicitly differentiate itself from sibling tools like accept_invoice or reject_invoice, which are similar state-changing operations.

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 required prerequisites (e.g., invoice must be in a certain state) or when signing is appropriate compared to accepting or rejecting. No alternatives or exclusions are noted.

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