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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so safety is covered. The description adds value beyond that: default 25 rows / hard cap of 200, the paging contract, and the underlying endpoint (POST /purchases/invoices/list – a read done via POST, which the annotation clarifies). It does not describe the response payload.

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?

Four tight sentences, front-loaded with purpose and capability, then field-naming convention, then pagination mechanics. No filler, though the endpoint string adds little for an agent that cannot make raw HTTP calls.

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?

No output schema exists, so the description carries return-shape burden, and it only implies rows come back without saying whether a total count or cursor is included. Pagination and field-naming guidance are solid, but an agent still can't predict the response envelope.

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 baseline is 3, but the description earns more by naming the Laudus field model with concrete examples (purchaseInvoiceId, docNumber, supplier.name, totals.total) that apply directly to fields/filter/order_by. It also repeats the paging derivation without restating the limit/offset bounds already in 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+resource ('List purchase invoices (facturas de compra)') plus the capability set (filters, sorting, field selection, paging). The list-vs-get distinction against laudus_get_purchase_invoice is implicit rather than stated, so it stops short of full sibling differentiation.

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 one concrete procedural guideline ('When a page is full, ask for the next one with offset = offset + limit'), which is real usage guidance. It never says when to prefer this over laudus_get_purchase_invoice or laudus_purchase_ledger, and states no exclusions.

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