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

readOnlyHint=true already tells the agent this is a safe read. The description adds the underlying endpoint (GET /Voucher) and semantic meaning for status and credit_debit codes, but says nothing about pagination defaults, rate limits, or auth needs. Adequate against an annotation that already carries the safety profile.

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?

Three short clauses, zero padding, and the purpose is front-loaded before the filter-code reference. Every sentence earns its place; the trailing endpoint note is a minor but harmless implementation hint.

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 10-parameter, zero-required list tool with no output schema, the description covers purpose and the non-obvious enum semantics, while the schema handles pagination and filtering parameters. It stops short of describing the return shape, though without an output schema that gap is minor.

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 baseline is 3, but the description goes beyond the schema by decoding the enum values the schema only lists: 50=draft, 100=unpaid/due, 1000=paid, and C/D=credit/debit. That mapping is genuinely useful domain knowledge not derivable from the raw enums.

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 vouchers") and clarifies the domain meaning of "voucher" as receipts and incoming/outgoing bills, which distinguishes it from sibling list tools like sevdesk_list_invoices or sevdesk_list_credit_notes. It does not explicitly name or contrast with those siblings, so it falls 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?

Usage is implied by the list semantics and the filter codes, but there is no explicit when-to-use guidance, no distinction from sevdesk_get_voucher for single lookup, and no note on paging strategy. The status/credit_debit code map helps the caller filter, but doesn't route between alternatives.

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