nwc_multi_pay_invoice

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

With no annotations, the description carries the full burden and excels. It discloses that each invoice is independently decoded and safety-checked, that the batch sum is checked against budget caps upfront, that no payments are sent if any pre-check fails, and that partial failures do not roll back settled invoices. This is rich behavioral detail that goes beyond a simple 'pays invoices' statement.

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?

The description is two sentences: the first states the core purpose, the second explains the safety checks and execution model. Every sentence earns its place with no redundancy or filler. The critical information is front-loaded.

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 multi-invoice payment tool with safety checks and no output schema, the description covers the essential behavioral context: pre-checks, budget caps, sequential execution, and no rollback. However, it leaves ambiguity about what happens when a single invoice fails—does the batch stop, skip, or continue? It says 'a failure mid-batch does not roll back already-settled invoices' but does not clarify whether subsequent invoices are still attempted. This minor gap prevents a 5.

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 the schema already documents the invoice string and amount_override_sats fields. The description adds value by explaining how the invoices array is processed: each invoice is checked independently, and the batch sum is budget-checked upfront. This clarifies the group-level semantics of the array parameter beyond what the schema's item description provides.

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 opens with 'Pay multiple bolt11 invoices sequentially in one tool call,' which clearly identifies the verb (pay), resource (bolt11 invoices), and scope (multiple, sequential). This distinguishes it from siblings like nwc_pay_invoice, which handles single invoices, and nwc_pay_lnurl/keysend for non-bolt11 methods.

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 description implies when to use this tool: when there are multiple bolt11 invoices to pay in a single call. It does not explicitly name alternatives or state 'for single invoice use nwc_pay_invoice,' but the phrasing 'multiple... in one tool call' provides a clear context. No exclusions or when-not-to-use are given, so it falls slightly short of a 5.

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