Biała lista VAT — wyszukaj po NIP

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

No annotations are provided, so the description carries the full burden. It does well on output content by enumerating the fields returned (name, VAT status, REGON, KRS, address, bank accounts, registration/deregistration dates), which is exactly what substitutes for the missing output schema. However, it says nothing about failure behavior when a NIP is not in the register, whether the optional snapshot date changes the result shape, or any auth/rate-limit constraints.

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?

A single dense sentence that front-loads the source of the data and then lists the payload. Nothing is wasted, though the field enumeration could be trimmed or moved to an output schema if one existed.

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?

Two parameters, full schema coverage, and no output schema – the description compensates by enumerating the return fields. The only material gap for an agent deciding how to call it is the not-found / error behaviour, which is minor for a read-only register lookup.

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% – both 'nip' (NIP kontrahenta) and 'data' (Data stanu RRRR-MM-DD, domyślnie dziś) are documented in the schema, so the baseline applies. The description adds no format details (e.g. NIP with or without dashes) beyond what the schema already states.

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 (returns taxpayer data) and a specific resource (Ministry of Finance VAT register / Biała lista), then enumerates the returned fields. An agent can distinguish it from a generic lookup, though it never names which sibling it is not (e.g. nip_waliduj for checksum validation or biala_lista_konto for account checks).

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?

There is no explicit when-to-use statement, no prerequisites, and no routing to alternatives, even though the sibling set contains two closely related white-list tools. The agent must infer the use case from the title alone.

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