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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds that each entry includes the amount to send, which is useful return-shape context, but it omits behavioral edges such as what happens for already-paid or expired invoices and whether methods can change over time.

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 sentence with no filler, front-loading the verb and the subject (coins and networks) and appending the amount detail last. Nothing in it is redundant with the title or annotations.

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 one-parameter, read-only tool with full schema coverage, no output schema and clear annotations, this is close to sufficient: it tells the agent what it gets back and how each entry is shaped. The only real gap is the missing pointer to select_invoice_payment_method as the natural next step.

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 100% and the schema itself explains that invoice_id comes from create_invoice, so the parameter is fully documented without the description. The description adds no further detail on the identifier's format or provenance, so the 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 specific verb (lists) and a precise resource (coins and networks payable for this invoice) plus the extra payload (amount per method). It is clear against generic siblings like get_invoice, but it never distinguishes itself from the closely related select_invoice_payment_method, which an agent could easily confuse with this read.

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?

Usage is implied by the wording ('for this invoice', 'the payer can use'), so an agent can infer this is the discovery step before paying. However, there is no explicit when-to-use, no mention that it precedes select_invoice_payment_method or create_payment, and no state prerequisite (e.g. only meaningful for an open invoice).

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