Rebillia MCP Server

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 indicates this is a write operation ('Charge', 'POST'), implying mutation, and specifies the amount format. However, it lacks details on permissions, side effects (e.g., invoice status changes), error handling, or rate limits, which are important for a payment tool.

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 front-loaded with the core purpose, followed by key details (endpoint, payment type, amount format, required parameters). It uses minimal sentences with zero waste, making it efficient and easy to parse for an AI agent.

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 payment tool with no annotations and no output schema, the description is adequate but incomplete. It covers the basic action and parameters but lacks behavioral context (e.g., what happens on success/failure, response format). Given the complexity of charging invoices, more details on outcomes or errors would enhance completeness.

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 schema already documents both parameters. The description adds value by clarifying the amount format ('AMOUNT IN CENTS: e.g. 5500 = $55.00') and emphasizing required fields, but does not provide additional context beyond what the schema specifies, such as invoiceId format or validation rules.

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 specific action ('Charge an invoice via offline payment') and resource ('invoice'), distinguishing it from sibling tools like 'charge_invoice' (likely for online payments) and 'void_invoice'. It specifies the payment method (cash/check/wire) and the API endpoint, making the purpose unambiguous.

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 implies usage context by specifying 'offline payment (cash/check/wire)' and the required parameters, suggesting this tool is for non-digital payments. However, it does not explicitly state when to use this versus alternatives like 'charge_invoice' or mention any prerequisites or exclusions, leaving some ambiguity.

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