Pay multiple invoices at once by creating a group invoice for Hostkey billing; submit invoice numbers and set confirm to true to complete payment.
Create a group invoice to pay multiple invoices at once (whmcs/mass_pay). MONEY.
| Name | Required | Description | Default |
|---|---|---|---|
| confirm | Yes | Must be true to run the operation. | |
| invoices | Yes | Array of invoice numbers |
Changes observed during successful MCP inspections.
v1.0.3Input schema / properties / invoices / descriptionPrevious value: -"Массив номеров инвойсов"New value: +"Array of invoice numbers"v1.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, openWorldHint=true, and destructiveHint=false. The description adds no behavioral context beyond restating the operation: it does not explain financial consequences, required permissions, the role of confirm=true (only in schema), or the outcome of paying invoices. The cryptic 'MONEY.' tag is unhelpful rather than informative.
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 main sentence is concise and front-loaded. However, the trailing 'MONEY.' is noise that does not earn its place and adds no actionable 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?
For a financial mutation tool with no output schema, the description is too sparse. It omits critical context such as what happens to funds, whether the operation is immediate or batch-queued, and any failure modes. Annotations cover the safety profile only at a high level.
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 both parameters are fully documented in the input schema. The description adds no meaning beyond what the schema provides—it does not clarify invoice number format or what confirm actually controls.
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 states a specific verb and resource: 'Create a group invoice' with the purpose 'to pay multiple invoices at once'. This distinguishes it from read-oriented billing siblings like get_invoice and get_invoices. However, it does not explicitly name an alternative or differentiate from similar mutation tools like apply_credit or create_addfunds_invoice.
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, no exclusions, and no prerequisites described. The phrase 'at once' implies a bulk-payment context but does not tell an agent when mass_pay is preferred over other billing operations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.