list_invoices

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

Annotations already carry the safety profile (readOnlyHint=true, destructiveHint=false), so the description's job is to add behavioral context, which it does: pagination via `page`, period bounding via filters, and the domain constraint that tax figures must be derived from invoices. No contradiction with annotations.

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 sentences with zero waste. The first front-loads the core action and output fields; the second packs pagination, filtering, and the key use-case context. Every clause earns its place.

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 simple tool with 3 optional parameters, no output schema, and no nested objects, the description is complete: it names the returned fields (compensating for the missing output schema), the pagination parameter, the period-filter parameters, and the strategic use case. Nothing needed 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 coverage is 100% — all three parameters (page, filter_to, filter_from) are individually documented, so the baseline is 3. The description mostly restates the schema ('Paginated via page', 'bound the period') and adds only the strategic context tying the filters to the revenue/VAT use case rather than new parameter-level detail.

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 verb and resource ('List issued invoices from Quipu') and enumerates the returned fields (number, issue_date, due_date, total, subtotal, payment status). It also distinguishes itself from the tax-related sibling by explicitly positioning this tool as the source for revenue/VAT figures.

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?

Gives an explicit decision rule: 'this is the tool to use when asked about revenue or VAT for a quarter,' backed by the rationale that Quipu has no endpoint returning tax models directly. It stops short of naming the alternative sibling (get_tax_summary) by name or stating when not to use this tool.

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