lago_list_credit_notesList credit notes, optionally filtered by customer. Lago API: GET /credit_notes.
| Name | Required | Description | Default |
|---|---|---|---|
| page | No | Page number for pagination. | |
| per_page | No | Number of records per page. | |
| external_customer_id | No | Filter by customer external id. |
Changes observed during successful MCP inspections.
Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, covering the safety profile. The description adds the API endpoint reference but no pagination behavior, ordering, or result-set characteristics beyond the read-only signal.
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 short sentences with the filter constraint front-loaded; no wasted words. The endpoint citation is marginal but harmless.
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?
Adequate for a simple list tool with readOnlyHint and full schema coverage, but it omits pagination defaults and result shape, and does not differentiate from the single-get sibling.
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 all three params are documented in the schema. The description only reinforces the customer filter, adding nothing beyond the schema. Baseline 3 applies.
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 clear verb+resource ('List credit notes') and adds the customer-filter capability. It does distinguish scope from the sibling lago_get_credit_note (single) vs this list tool, though without naming it explicitly.
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 phrase 'optionally filtered by customer' implies when the external_customer_id filter applies, but there is no explicit when-to-use vs lago_get_credit_note guidance or when-not guidance.
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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