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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-query behavior are covered structurally. The description adds one genuinely useful exclusion ('never returns WHOIS contact data') and implies a live/real-time lookup, but says nothing about latency, rate limits, or failure modes of that live path.

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 with no filler, and the core action is front-loaded. The WHOIS caveat is useful but sits where a return-value sentence would be more valuable.

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?

A one-parameter read tool with annotations and no output schema needs little, but the description never indicates what the check yields (availability flag, reason, suggestions), leaving the agent to guess at the result shape. The input normalization requirement also remains unresolved.

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 0% and the only signal the description adds is the word 'normalized', which hints that input must be pre-normalized (no protocol, lowercase, maybe punycode) without stating the rule. With one simple string parameter, this is a modest but real gap rather than a failure.

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+resource ('Check a normalized domain') and ties it to the live DotMoose lookup path, so an agent can distinguish it from quote/publish siblings. It never explicitly says 'availability' in the body and leaves 'normalized' undefined, so the intent is clear but slightly under-specified.

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?

No when-to-use or when-not-to-use guidance, and no routing to siblings even though quote_domain is the obvious adjacent alternative once a domain is known to be available. The agent has to infer that this is the pre-check step.

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