pay_billRecord a payment against a bill by providing the bill ID, amount, payment date, and optional payment method to update the accounting ledger.
Record a payment against a bill.
| Name | Required | Description | Default |
|---|---|---|---|
| amount | Yes | Payment amount | |
| bill_id | Yes | Bill ID to pay | |
| payment_date | Yes | Payment date (YYYY-MM-DD) | |
| payment_method | No | Payment method (bank_transfer, card, cash, other) |
Changes observed during successful MCP inspections.
v0.2.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already communicate readOnlyHint=false, destructiveHint=true, and idempotentHint=false, and the description is consistent with those. It adds only minimal context by naming the bill as the affected target, but it does not describe consequences such as updating the bill balance or marking it paid.
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 clear sentence with no filler or redundant wording. The action is front-loaded and every word contributes to meaning.
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?
The schema and annotations cover invocation details and safety profile, making the tool minimally viable. However, there is no description of return behavior or side effects, and the lack of usage guidance means an agent has little help deciding between this and related sibling tools.
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%, with all four parameters documented, including the date format and payment method options. The description itself adds no extra parameter meaning beyond what the schema already provides.
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 uses a specific verb and resource: 'Record a payment against a bill.' This clearly identifies the operation as bill-payment recording, though it does not explicitly distinguish it from related tools like create_transaction or update_transaction.
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 provides no guidance on when to use this tool versus alternatives, no preconditions (e.g., bill must exist), and no exclusions. It does not mention that general payment recording might belong in create_transaction instead.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.