invoices_list_creditsCustomers' credits, prepayments and overpayments, newest first: what each was, what is left, its VAT and how it was used or paid back. Filter by customer, or status (open, used, refunded, void, all; default open). Free.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| offset | No | ||
| status | No | open | |
| customer | No | The customer: a CRM contact or company, or the email or name on their invoices. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the read-only, idempotent, non-destructive profile, and the description adds real context beyond that: 'newest first' ordering, the fact that it is free, and the payload contents (original amount, remaining balance, VAT, usage/repayment history). No permission or pagination behavior is disclosed, but the added value is substantial.
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?
Two tight sentences: contents and ordering first, then filtering and the free-cost note. No filler or repetition of the title.
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?
With no output schema, the description correctly spells out what each record contains, and it covers the key status filter. What is missing is pagination guidance (limit/offset semantics and defaults), a noticeable gap for a list tool.
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 coverage is only 25%, but the description adds meaning for the status enum (open/used/refunded/void/all plus the default) and confirms customer filtering; limit and offset remain unexplained in both schema and description. Baseline 3 fits given the partial compensation.
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 names a specific resource (customer credits, prepayments, overpayments) and a sort order (newest first), making the listing intent unambiguous. It does not, however, differentiate itself from related siblings such as purchasing_list_credits or invoices_use_credit.
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?
It mentions filtering by customer or status with the default (open), which implies how to narrow results, but never states when to use this tool versus alternatives like invoices_get or invoices_use_credit, nor any prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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