Get one voucher with its positions

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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint, so 'Read-only' adds little. The valuable addition is that VAT treatment and per-position tax rates are returned decoded rather than as raw codes, which tells the agent how to interpret output and is not derivable from the annotations or schema.

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?

Front-loaded single sentence that covers scope, contents, and transformation behavior, followed by a short safety tag. The trailing 'Read-only.' duplicates the readOnlyHint annotation, a small redundancy but nothing else is wasted.

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 must convey return shape, and it does name the key contents (line items, decoded VAT treatment, per-position tax rates). It stops short of describing behavior on a missing or invalid voucher id, which is the main remaining gap for a single-record getter.

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?

Only one parameter, voucherId, already documented at 100% schema coverage as 'Numeric voucher id.' The description adds no format, range, or error semantics beyond that, so the schema carries the load and the baseline 3 applies.

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?

A specific verb (Fetch) plus resource (a single voucher) and an explicit statement of what comes back (line items, VAT treatment, per-position tax rates). The word 'single' implicitly separates it from sevdesk_list_vouchers, but no sibling is named, so differentiation is inferred rather than stated.

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 only implied: an agent can infer this is the detail-fetch counterpart to the list tools when full position-level data is needed. There is no explicit when-to-use, when-not-to-use, or named alternative such as sevdesk_list_vouchers.

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