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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-network behavior are covered structurally. The description usefully discloses provenance (two named Polish registers merged), but says nothing about failure behavior when an identifier has no match, or about the cost/latency of hitting two upstream sources.

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 sentences, front-loaded with the outcome and followed by the input constraint. No filler, no restatement of the tool name.

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?

With no output schema, the description should hint at the shape of the "normalized profile" (which fields are unified across the two registers), and it doesn't. Input side is adequately covered, output side is not.

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 0% and the schema marks no parameter as required, so the description carries real weight with the "one of nip, regon, krs" constraint, which the schema does not express. It still does not explain identifier formats (e.g. 10-digit NIP) or what happens if more than one is supplied.

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 the concrete action and resource: merging the MF white list and KRS registers into a single normalized company profile. An agent can distinguish it from the single-source siblings (get_krs_extract, check_vat_whitelist), though the description never names them explicitly.

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?

"Provide one of nip, regon, krs" covers the input requirement but there is no when-to-use guidance relative to the heavily overlapping siblings (get_krs_extract, check_vat_whitelist, vies_check). Nothing tells the agent when the combined profile is preferable to a single-register lookup.

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