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

With no annotations, the description carries the full burden and does so well: it discloses GDPR-driven data limitations for natural persons (address reduced to town, accounts reduced to a count, no REGON/registration date/PKD, ceidg always null) and explains the privacy field. It omits operational details such as auth requirements or error behavior, keeping it below a 5.

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 is front-loaded in the first clause, and the following GDPR detail is genuinely useful rather than filler. The second sentence is dense with nested parentheses, which slightly hurts readability but the content earns its place.

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 single-parameter, read-only lookup with no output schema, the description supplies the return-value caveats (reduced address/account data, null ceidg, privacy field) an agent needs. It is close to complete, missing only explicit return-shape/error expectations.

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%, so the single NIP parameter is already documented as a 10-digit Polish NIP. The description adds no format or constraint detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resources: check VAT status (White List) and KRS data for a Polish company by NIP. It is clear what the tool does, and it routes one sub-case (specific bank account) to the sprawdz_rachunek sibling. It does not differentiate from closely-related siblings like sprawdz_lista_nip or sprawdz_regon.

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?

Gives clear context for use (lookup of a Polish entity by NIP) and an explicit alternative for one case, pointing to sprawdz_rachunek for checking a specific account. It stops short of stating when to prefer this over the other NIP/REGON/White List lookups or any exclusions.

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