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

Beyond the readOnly/destructive annotations, it discloses that only the supplied call material is read (no wallet, chain, market, bank or counterparty lookup) and that no money movement occurs, plus the paid-URL price, free-call allowance, wallet-proof binding, and the Ed25519 signed receipt. These are exactly the operational facts an agent needs that annotations cannot express.

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?

Purpose, scope limits, and sibling routing come first, with payment and contract details after, so the important content is front-loaded. It is dense but nearly every clause carries operational meaning, though the endpoint path and human-page URL add minor bulk.

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?

With no output schema, the description still describes the return: bucketed totals, oldest-first overdue listing, total at risk, a verdict enum, and a signed receipt. Combined with the access, pricing, and proof requirements, nothing essential for correct invocation is missing.

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 100%, so the schema already documents label, currency, invoices, and current_date. The description's enumeration of invoice fields (counterparty, amount, currency, issue date, due date) and the current-date input largely restates the schema rather than adding format or fallback rules, so the baseline of 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?

The description states a specific action (submit open invoices plus a current date to get a signed aging brief) and names the exact output structure: bucketed totals, overdue invoices oldest first, and total at risk. It also explicitly contrasts with the invoice creation (create_invoice) and matching (wever_invoice-payment-match) siblings, so an agent can separate this from wever_invoice-brief or wever_invoice-check.

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?

It declares the scope as "Open-invoice analysis only" and routes invoice creation and payment matching to the correct sibling tools, which is usable when-to-use guidance. It does not explicitly say when to prefer this over adjacent reporting siblings like wever_invoice-brief or wever_expense-close-pack, so the exclusion set is partial rather than exhaustive.

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