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

Annotations cover the safety profile (readOnlyHint, openWorldHint), and the description adds real value by listing exactly what is returned — entity, registration number, type, name status and active flag — which matters since there is no output schema. It omits result limits, pagination, and behaviour on no-match.

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 tight sentences: the first front-loads the register, the lookup keys and the return fields; the second states the purpose. No filler.

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 read-only, zero-required-parameter lookup with no output schema, the description covers return fields and intent well. The remaining gap is ambiguity against the cyprus_company_name_check sibling and no guidance on partial-match results.

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 all three parameters are already documented, including the sound_like default. The description only restates the two lookup modes and adds no syntax or match-behaviour detail beyond the schema, so the baseline 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 resource — searching the Cyprus Registrar of Companies public register by name or registration number — and enumerates the returned fields. It does not, however, distinguish itself from the sibling cyprus_company_name_check, which an agent would reasonably confuse it with.

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 a clear usage context: verify that a company a user mentions actually exists and is on the register. It stops short of stating when to prefer the sibling cyprus_company_name_check or what happens when neither name nor number is supplied.

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