Get one voucher with its positions

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

The description explicitly states 'Read-only', indicating no side effects. It also adds context about the return format (decoded VAT/tax rates). However, it does not mention error handling or what happens if the voucher does not exist.

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?

The description is two sentences long with no wasted words. The main action is front-loaded, and every sentence provides essential information.

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?

The description adequately covers the tool's behavior for a simple read operation. It explains what is fetched and the additional decoded information. Without an output schema, the description provides sufficient context for an AI agent to understand the return value.

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?

The input schema already has 100% coverage for the single parameter 'voucherId', describing it as 'Numeric voucher id.'. The description does not add further parameter details but is sufficient given the schema completeness.

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?

The description clearly states the action ('Fetch a single voucher'), resource ('voucher'), and scope ('including its line items, with the VAT treatment and per-position tax rates decoded'). It distinguishes from sibling tools like 'sevdesk_list_vouchers' which focuses on listing.

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 does not provide any guidance on when to use this tool versus alternatives. It does not mention when to use this over 'sevdesk_list_vouchers' or other tools, nor does it specify any prerequisites or conditions.

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