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

Annotations only declare readOnlyHint=true, so the description carries the extra load and does so usefully: it decodes the status codes (100 draft, 200 open/delivered, 750 partially paid, 1000 paid) and names the backing endpoint (GET /CreditNote). It says nothing about pagination behavior or result volume caps, keeping it from a 5.

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: the core purpose and filter dimensions come first, the status-code legend and endpoint follow. No sentence is wasted and everything is front-loaded.

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 read-only list tool with full schema coverage and an explicit readOnlyHint, the definition covers purpose, filters, and status semantics adequately; no output schema is needed to explain returns. Only the omission of paging/result-volume guidance keeps it from full completeness.

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 all nine parameters and the baseline is 3. The description adds genuine value only for `status` by translating the enum codes into human meanings; the remaining filters are merely enumerated, adding nothing 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 ('List') and resource ('credit notes'), and even supplies the German synonym ('Gutschriften'), making the target resource unambiguous against siblings like list_invoices or list_vouchers. It does not explicitly contrast itself with those siblings, so it stops just short of a 5.

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 list of filterable dimensions implies a querying use case, but there is no explicit when-to-use, when-not-to-use, or named alternative among the many other list_* sibling tools. Usage is inferable for a straightforward list tool but never stated.

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