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

Beyond the readOnly/openWorld/idempotent annotations, it discloses non-obvious behavior: per-section failure isolation (a failed section returns an object with an `error` field while the rest is unaffected), the latency tradeoff of wait=true (~20 s), and subdomain ordering (live hosts with IPs first). These are exactly the runtime traits annotations don't capture.

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 full report scope, then usage, then failure behavior and the wait tradeoff. No filler and nothing buried.

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?

An output schema exists, so return structure needn't be described, and the description still adds the error-field convention and the wait latency bound. For a read-only aggregate lookup, everything an agent needs to select and call it correctly is present.

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 carry parameter meaning, and it explains wait (wait for all subdomain sources vs. fast first result) — but only partially, since the ~20 s ceiling is a skew-check. `domain` is self-evident, but `subdomain_limit` is never described anywhere, leaving one of three parameters semantically empty.

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 concrete verb (report) and resource (domain) and enumerates exactly the five sections produced — WHOIS/RDAP, DNS, SSL, subdomains, email authentication — which map one-to-one onto the sibling tools. An agent can tell this is the aggregate one-call variant of dns_records/whois_lookup/ssl_certificate/subdomains/email_security without opening any schema.

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?

It gives clear usage contexts ('triage a suspicious domain', 'profile a company's domain'), which is strong routing guidance. It stops short of explicitly naming the siblings as the alternative when only one section is needed, so the when-not is left to inference from the section list.

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