Open items (unpaid sales invoices)

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description still adds real behavioral value: result ordering (oldest due date first), per-currency totals, and the warning that amounts are gross rather than net — the latter is the kind of caveat an agent would otherwise get wrong.

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 tight sentences with zero filler, and the core scope is front-loaded before the ordering and gross-amount details. Every clause carries information an agent needs.

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 usefully characterizes the return shape: ordering, currency-level totals, and gross amounts. It stops short of stating pagination behavior or the fields present on each invoice, but for a two-optional-parameter read tool this is close to sufficient.

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%, with both optional parameters fully documented in the schema, so the baseline is 3. The description's mention of 'open and overdue' loosely maps to overdueOnly but adds no syntax, matching behavior, or default information beyond the schema.

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 ('Lists unpaid sales invoices') plus the domain source (Lexware Office) and the exact scope ('open and overdue receivables'). No siblings exist, so no differentiation is required, and the phrase 'open and overdue' makes the scope unambiguous.

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?

Usage is implied by the scope statement but never made explicit — there is no 'use this when' framing or exclusion. The clause 'net amounts need the voucher detail' is a useful pointer toward a different tool for a related need, which is the only routing signal present.

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