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

Annotations already establish the tool as read-only, idempotent, and non-destructive. The description adds behavioral context beyond that by disclosing that the tool performs subdomain probing and produces a health verdict, which implies active enumeration and synthesized judgment. It does not mention latency or cost, but it provides meaningful disclosure of the tool's composite 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?

One dense, front-loaded sentence communicates the full scope and workflows with no filler. Every element earns its place.

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 three-parameter composite tool with no output schema, the description provides sufficient context for an agent to select and invoke it correctly. It enumerates all major data domains and gives workflow context. The main gap is the lack of explicit treatment of the skip parameters and the exact nature of the health verdict, but this does not critically impair usage.

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 0%, so the description must compensate. The required 'domain' parameter is self-evident, and 'skip_whois' and 'skip_subdomains' are reasonably inferable from their names and from the WHOIS/subdomain-probe components mentioned in the description. However, the description does not explain how skipping affects the overall profile or health verdict, leaving some ambiguity.

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 states the tool produces a comprehensive DNS + WHOIS + security + hosting + email-infrastructure + subdomain-probe + health-verdict profile for a domain in one call. This distinguishes it from narrower sibling tools like dns_lookup, dns_whois, and dns_reputation.

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 identifies concrete workflows ('Sales-intel and security-audit workflow') and emphasizes 'one call', clearly implying this tool is for broad investigative use cases rather than single-aspect DNS queries. It does not explicitly name alternative tools or exclusion conditions, but the use context is clear.

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