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

Annotations already declare readOnlyHint=true, so the safe-read profile is covered. The description adds value beyond that: result ordering (newest first), the exact returned fields, package-availability constraint, and the API-key/access requirement. It stops short of describing pagination behavior despite exposing a cursor parameter.

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 sentences that are front-loaded with purpose and free of fluff; each sentence carries information (scope, ordering, return fields, prerequisites). The first two sentences overlap slightly on the 'sales invoices of one division' framing, which costs it a point.

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 list tool with annotations supplying the safety profile and no output schema, the description covers return fields, ordering and the preconditions an agent must satisfy (package availability, API key). Pagination via cursor is not explained, a minor gap given the cursor param is schema-documented.

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 limit, cursor, division, customer, from_date and to_date are each already documented in the schema. The description only restates the date-range/customer filtering at a high level, adding no syntax or format detail beyond the schema, which is the baseline 3 case.

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 sales invoices of one division') plus the scope (newest first, filtered by date range or customer), so the agent knows exactly what comes back. It references the sibling send_sales_invoice (whose input this feeds) but does not explicitly contrast itself with get_sales_invoice or create_sales_invoice, 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?

The description says it can be filtered by date range or customer, which implies the retrieval context, and warns that 'the endpoint exists only in some Exact packages' plus the API-key access requirement. However, it never says when to prefer this over get_sales_invoice or the other list_* siblings, so alternatives are left to inference.

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