PayPing: create invoice

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

Annotations already declare destructiveHint=true, openWorldHint=true, idempotentHint=false and readOnlyHint=false. The description adds genuinely additive context beyond them: 'Creates real data: confirm customer, items and prices with the user before calling', which flags real-world side effects and a verification step. It stops short of discussing reversibility or whether duplicates can be created, so not a 5.

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?

Three tight sentences with the core behavior and return value front-loaded, followed by the routing hint and the safety caution. No redundancy; every clause carries information.

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?

An output schema exists, yet the description still usefully names the returned code/payCode/url. For a destructive, non-idempotent mutation it supplies the needed caution, so an agent can call it correctly. Only minor gaps (e.g., currency/tax implications, error cases) remain.

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 60%, and the description only implies the customer is 'saved' (customer_code) and lists return fields; it adds no meaning for items, notes, title or due_date beyond what the schema already documents. With the schema doing most of the lifting, baseline 3 is appropriate.

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?

States a specific verb and resource (create an invoice) plus its scope: for a saved customer, returns code/payCode/url. It also explicitly distinguishes itself from payping_send_invoice by noting the invoice 'is not sent', so an agent can differentiate it from the sibling without opening either schema.

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?

Gives an explicit alternative and the condition that selects it: 'It is not sent; use payping_send_invoice or share the url.' It also states a precondition for calling ('confirm customer, items and prices with the user'). Routing and prerequisites are both covered.

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