List payments

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so safety is covered. The description adds real context beyond that: result ordering (newest first), the exact status vocabulary (received, in_review, verified, failed), and the shape of each record, which matters because there is no output schema.

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 paragraphs, front-loaded with the core behavior and returning field detail where it is most useful. The first line and the field list in the second overlap slightly (both mention amount and invoice), but the redundancy is minor and the field list earns its place given no output schema.

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 four-parameter list tool with no output schema, the description does the important work: it enumerates returned fields and status values. It stops short of describing pagination behavior (the 25 default, 100 cap, how cursor drives the next page), which an agent would need to page correctly.

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 75% – cursor, project_id and customer_id are documented, though limit (default 25, cap 100) is bare. The description adds no syntax or format for these parameters, but it does implicitly signal that invoice-level filtering is not offered here, which is a small piece of negative guidance. Baseline 3 applies when the schema carries most of the load.

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 first line states a specific verb and resource (listing payments received on invoices) plus the ordering (newest first) and the fields returned (amount, method, invoice). It also names the sibling it is not, get_invoice, so an agent can separate the two without opening either schema.

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 closing sentence gives an explicit alternative and the condition that selects it: get_invoice shows the payments of a single invoice. The project/customer filtering in the schema implies the bulk-use case, but the description never spells out when to prefer this tool over that filtering or over list_invoices.

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