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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, covering the safety and network profile. The description adds one genuine behavioral trait beyond that—'resolved in parallel'—but says nothing about timeouts, partial failures, or rate limits for a live-DNS tool.

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?

A single dense sentence, front-loaded with the resource and immediately followed by the record types produced. No filler or redundancy.

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-value documentation is not required, and the description lists record types plus the parallel-resolution behavior. For a single-parameter read tool this is nearly sufficient, with the only real shortfall being the undocumented domain format.

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% and the single 'domain' parameter is undocumented in the schema. The description says 'for a domain' but adds no format or syntax guidance (e.g., apex vs subdomain, trailing dot, URL handling), so it fails to compensate for the coverage gap.

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 clear verb+resource ('DNS records for a domain') and enumerates the concrete record types returned (A, AAAA, MX, TXT, NS, CAA, SOA), so the agent knows exactly what data it yields. However, it does nothing to distinguish itself from the sibling domain_lookup, which likely retrieves overlapping information.

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 guidance on when to pick this tool over the similarly-named siblings (domain_lookup, email_security, ssl_certificate). No prerequisites, no exclusions, no alternative routing—the agent must infer usage entirely.

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