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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine value beyond that by disclosing the output's epistemic limit (the Registrar alone decides availability) and by describing what is returned: raw register results plus the rules engaged. Rate limits or coverage breadth of the register are not mentioned.

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?

Three tight sentences, front-loaded with the action and closed with the most decision-relevant caveat. Every sentence carries distinct information; nothing is redundant with the title or schema.

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 carries return-value burden and does so at a high level ('what the register returned and which rules the name engages'). The explicit disclaimer about availability fills the most important gap for an agent interpreting results. Finer detail on result shape would make it 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 both parameters (proposed_name, sound_like) are already fully documented in the schema. The description adds no parameter-level detail of its own, so the baseline of 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?

The description states a specific verb and resource: screening a proposed name against the Registrar's naming criteria plus a search of the public register. This is clearly distinct in substance from cyprus_company_lookup (existing entities), but the description never names a sibling or explicitly contrasts with it, leaving the differentiation implicit.

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?

Usage context is clear: this is a pre-incorporation screening step, and the description sets an explicit boundary on what the result means ('Does not state that a name is available'). However, it never names an alternative tool or states a when-not condition beyond that output caveat.

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