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

With no annotations, the description carries the full disclosure burden. It adds a meaningful behavioral constraint ('Never invent personal identities, birth details, or corporate connections'), which is genuine value beyond the schema, but says nothing about result shape, pagination behavior, or data-freshness limits that an agent would want before invoking a registry lookup.

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 purpose and followed by operating rules; nothing is padded. The rules sentence is somewhat generic but does earn its place given the absence of annotations.

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 9-parameter, zero-required search tool with no output schema, the description adequately frames the domain and flags the need to gather criteria, but does not convey what a result contains or how limit/offset pagination behaves. It is minimally sufficient rather than complete.

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 every parameter is already documented in the schema, giving a baseline of 3. The description refers only vaguely to 'criteria' and adds no format or matching details beyond what the schema fields already state.

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 (search) and resource (Croatian Registry of True Owners / RSV) and clarifies the direction of the lookup: discovering companies tied to an individual owner or representative, which separates it from company-centric siblings like search_companies or get_company_true_owners. It stops short of naming those siblings 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?

The rule 'If criteria are missing, interview the user first' gives one clear usage condition, but there is no guidance on when to prefer this over search_companies, nor when NOT to use it. Usage is implied rather than fully specified.

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