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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuinely useful behavioral context the annotations cannot: a $0.50 USDC charge on Base via x402, i.e. a paid call. It still omits what the triage returns and whether payment is per-call or per-invoice.

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 sentences, zero filler, with the core purpose front-loaded before the pricing clause. Nothing could be cut without losing information.

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?

There is no output schema, so the description carries the burden of explaining what the triage returns (aging buckets, recommended actions) and it does not. Combined with four undocumented required parameters, an agent cannot predict the result shape or input semantics.

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 description coverage is 0% and all four parameters are required and undocumented. The description adds nothing about invoiceNumber, clientReference, amount, or daysOverdue – notably the odd negative-minimum daysOverdue (-365) is left unexplained, so the description fails to compensate for the coverage gap.

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+resource: 'invoice aging and next-action triage', qualified as deterministic. None of the siblings (base_*, audit_*) overlap with invoice triage, so differentiation is implicit rather than stated. 'Next-action triage' remains somewhat vague about what advice is produced, keeping it short of a 5.

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?

No when-to-use context, no prerequisites, and no alternative named despite 21 sibling tools. The only guidance is the payment term, which is not usage guidance.

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