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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds a genuinely useful negative disclosure ("never returns WHOIS contact data") and implies a live network lookup, but says nothing about whether the result is a boolean, a price, or suggested alternatives, nor about rate/latency behavior.

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 short sentences, front-loaded with the action and free of filler. The second sentence earns its place as a scope-boundary disclosure, though the phrasing could be folded more tightly into the first.

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 one-param read-only tool with annotations covering safety, the core is present, but the description omits what the response conveys and how the caller should normalize the domain string. Without an output schema, those gaps matter for correct invocation.

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?

With one parameter and 0% schema description coverage, the description must carry the burden, and it offers only the adjective "normalized" without explaining the normalization rules (strip scheme, lowercase, punycode/IDN handling). It hints at the required input format but leaves the operative detail unspecified.

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 ("Check") and resource ("a normalized domain") against the live DotMoose lookup path, which distinguishes it from the pricing-oriented sibling quote_domain. The word "availability" appears only in the name/title, so the description alone doesn't quite declare the outcome the tool produces.

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?

There is no explicit when-to-use or when-not guidance, and the obvious alternative (quote_domain) is never named despite being in the sibling set. An agent must infer that this is the pre-pricing availability check rather than the quoting step.

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