Change a voucher's tax rule

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

With no annotations, the description fully discloses behavior: it is a write operation that can change data, it refuses enshrined vouchers and wrong-side rules, it verifies the result, previews with dryRun, and preserves position rates. It warns about foreign-currency recalculation at today's rate. All behavioral traits are explicitly stated.

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 front-loaded with purpose and contains substantial information, but is slightly lengthy. While every sentence adds value, it could be trimmed slightly without losing clarity. Still, it is well-structured and informative.

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?

Given the complexity of the operation (changing tax rules with guardrails) and the lack of an output schema, the description is fairly complete. It explains what happens to positions and currency, but does not detail the response format or how verification results are returned. Still adequate for selection.

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. The description adds value by explaining that voucherId is numeric, giving a concrete example for taxRuleId (12 for Reverse Charge), and clarifying dryRun previews the request. This goes beyond the schema's basic descriptions.

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 tool's purpose: rebooking a voucher onto a different VAT rule. It specifies the resource (voucher) and the action (changing tax rule) with specific examples like 'Reverse Charge §13b, taxRule 12'. It distinguishes itself from sibling tools, which are primarily for listing, creating, or auditing vouchers, not modifying VAT rules.

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?

Explicitly states when to use (draft vouchers) and when not to use (paid/booked vouchers, enshrined vouchers, wrong-side rules). Provides an alternative: 'Correct paid vouchers in the sevDesk UI instead.' Also mentions guardrails and verification, giving clear context for appropriate use.

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