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

With no annotations, the description carries the full burden for a write/persistence operation. It does disclose that the invoice is registered and what comes back (id, amount, payment address, status), but says nothing about permissions, whether the exchange rate is locked at creation, duplicate handling, or what happens if rate lookup fails.

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?

Three short sentences, each earning its place: identity/action, currency default and rate mechanics, then return fields. Front-loaded with the mutation and scoped precisely, with no filler.

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 mutation tool with no annotations and no output schema, the description covers the action, persistence, defaults, and return shape, which is most of what an agent needs. Remaining gaps are permissions and rate-lock/error behavior, which matter for correctly interpreting a later payment.

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%, so baseline is 3, but the description adds genuine meaning: it explains that the payment currency defaults to XMR converted at market rate, clarifying how monto_usd (always USD) maps to the actual payment amount. It adds nothing about cliente or concepto, which the schema already documents.

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 and resource: creates an invoice in the name of ONE (AliceLabs LLC) and registers it, with the issuer identity spelled out. The operation is clearly distinct from payment/listing siblings, though no sibling is named to reinforce that distinction.

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?

Provides implied usage context by stating the default is XMR at market rate with USD also available, which tells the agent when the default applies. However, it never says when to prefer this tool over one_pagar or the listing tools, nor any preconditions for issuing an invoice.

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