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

Beyond the read-only and non-destructive annotations, it discloses document inclusion and exclusion rules, approval defaults, warnings, reverse-charge treatment, DUZP fallback logic, and turnover exclusions. These details expose substantial calculation and output behavior rather than merely restating the safety hints.

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 purpose and key limitation are front-loaded, and nearly every sentence supplies a distinct operational rule. The long single paragraph is dense and harder to scan than a short structured summary, so its presentation is not optimal despite the low amount of redundant wording.

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 complex financial report with no output schema, it covers the principal outputs, warnings, exclusions, tax-date logic, and turnover field unusually well. The remaining gaps concern period-selection edge cases and explicit sibling routing rather than core behavior needed for a normal call.

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 schema already covers most arguments, and the description repeats much of the companyId and includePending behavior. It adds useful consequences of month selection and explains how documents are assigned to the selected period, but does not clarify the year-only default or how conflicting month and quarter values are handled.

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 opening defines a VAT summary for one company and period, including tax bases, VAT by rate, input/output amounts, and CZK currency. 'Podklad pro priznani, ne priznani samotne' clearly distinguishes it from filing-oriented siblings such as generate_vat_filing and get_vat_filing.

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 establishes the use case as supporting preparation of a VAT return, not producing the return itself, and also identifies monthly reporting and non-payer turnover use cases. It does not explicitly route users who need an actual filing to generate_vat_filing or get_vat_filing, so the alternative-selection guidance is incomplete.

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