get_payment_gateway

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered, but the description adds nothing beyond the basic purpose: no indication of what the result contains (gateway list, statuses, availability), no auth or scoping notes. The bar is lower with annotations present, yet no extra behavioral context is supplied.

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?

A single short sentence plus an endpoint reference; nothing is wasted and it is front-loaded. It is efficient, though the endpoint token adds little value to an agent selecting the tool.

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 single-parameter read tool with full schema coverage and safety annotations, the description is minimally adequate. It omits the action verb and any hint of return shape, which matters since no output schema exists.

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?

Only one parameter exists and schema description coverage is 100% ('Invoice number'), so the schema carries the semantics. The description's phrase 'for a specific invoice' merely restates the parameter's role and adds no format or usage detail.

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 the resource ('Payment methods for a specific invoice') but uses a noun phrase with no verb, leaving it ambiguous whether it lists payment gateways available to pay the invoice or methods already used. It also does not distinguish this from nearby billing siblings such as get_invoice or get_transactions. Understandable, but vaguer than a clean verb+resource statement.

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?

There is no when-to-use guidance, no mention of prerequisites (e.g., the invoice must exist or be unpaid), and no reference to any alternative tool. The agent is left to infer the context entirely.

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