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

With no annotations provided, the description carries the full burden. It discloses the legitimate-interest regime and that purpose is logged, adding behavioral context. However, it does not mention the output format, potential fees (such as the interpret parameter), or error conditions, leaving significant gaps.

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 description is two sentences and front-loads the key resource and output details. It could be phrased more directly (e.g., starting with 'Returns...'), but it avoids fluff and is efficiently structured.

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?

Given the absence of an output schema and annotations, the description reasonably covers the resource, key output fields, and legal regime. The parameters are fully documented in the schema, so the description need not repeat them. However, some behavioral details (fees, response format) are absent, preventing a 5.

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%, so the baseline is 3. The description's mention that 'a purpose is required and is logged' mirrors the schema's existing parameter description, adding no new semantic value. The interpret parameter is not mentioned in the description, but the schema fully documents it.

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 clearly identifies the resource (beneficial owners of a Lithuanian legal entity) and the key output fields (ownership percentages, control basis), distinguishing it from siblings like court cases or real estate. However, it lacks an explicit action verb like 'Get' or 'List,' relying on the noun phrase 'Declared beneficial owners.'

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 description states that the tool operates under the legitimate-interest regime and requires a purpose, which implies when use is appropriate. It does not explicitly name alternatives or state when not to use this tool, leaving the boundary with get_participants or lookup_company unclear.

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