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

No annotations, so the description carries the burden. It usefully discloses the upstream resolver (Cloudflare DoH) and cost model ($0.02/call, USDC on eip155:8453), which are meaningful behavioral facts. However, it omits caching/rate-limit behavior, failure modes (NXDOMAIN), and response shape for a network call whose results change over time.

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?

Appropriately short, but wastes a sentence restating 'Cloudflare's DNS-over-HTTPS resolver' and contains a broken clause ('needs to real DNS records'). The record-type list is useful and front-loaded, but the redundancy and error reduce quality.

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 simple two-parameter, no-annotation, no-output-schema lookup, the description covers purpose, record types, upstream source, and cost. Only minor gaps remain (return format, edge-case behavior), so it is largely complete for the tool's complexity.

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 100%, with the type enum already documented in the schema, so the schema does the heavy lifting. The description lists the record types but adds no syntax, format, or normalization guidance (e.g. whether 'domain' accepts subdomains or full URLs) beyond the schema. Baseline 3.

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 ('Query') and resource ('live DNS records'), enumerating the supported record types (A, AAAA, MX, TXT, NS, CNAME, SOA) and the upstream resolver (Cloudflare DNS-over-HTTPS). It does not explicitly differentiate from the adjacent security_mx_lookup sibling, leaving partial ambiguity about overlap, so it falls short of a 5.

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?

Offers use cases ('Domain validation, email deliverability pre-checks and infrastructure discovery') but the operative when-to-use sentence ('Use this when an agent needs to real DNS records via Cloudflare DNS-over-HTTPS') is circular and grammatically broken. No alternatives are named, e.g. security_mx_lookup for MX-only or crypto_ens_resolve for ENS names.

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