issue_credit_note

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

With no annotations, the description carries the full burden and does disclose non-obvious domain behavior: positive amounts on the document, deduction in VAT reporting in the correction-date period, and the exact file format produced. It stops short of stating preconditions (must the original be issued/paid?), whether the original invoice is flagged or left untouched, or failure modes such as crediting more than the invoice total.

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 short paragraphs, twenty-odd words each: the first states what is produced, the second states when to use it and the accounting consequence. Nothing is redundant and the core action 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?

An output schema exists and all four parameters are documented, so the description only needs to cover intent and side effects. Those are largely covered, but for a mutation tool with no annotations a sentence on preconditions and on what happens to the original invoice would close the remaining gap.

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%, and every property — original_number, reason, issue_date and the lines sub-object — carries its own Czech explanation in the schema. The description adds no parameter-level detail beyond that, so the baseline 3 applies; it does at least reinforce the positive-amounts convention that governs 'lines'.

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 names a specific verb and resource ('Vystaví opravný daňový doklad (dobropis) k vydané faktuře') and pins down the output artifact precisely: PDF/A-3 with ISDOC, DocumentType 2, no QR. That level of specificity makes it unmistakable against siblings like issue_invoice or cancel_invoice.

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?

It gives an explicit routing rule: 'Použij místo storna, když už faktura odešla odběrateli' — use this instead of cancellation once the invoice has left to the customer. The alternative (cancel_invoice/storno) is named and the selecting condition is stated, so the agent does not have to infer it.

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