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

With no annotations, the description must carry the full behavioral burden. It usefully discloses the return contents (answers with TTLs), the DoH transport, and per-call cost of 0.001 USDC via x402 — real value beyond structured fields. However, it says nothing about failure behavior (NXDOMAIN, timeouts), rate limits, or what a 402 response body looks like, leaving an agent to discover the error path at runtime.

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 zero filler, and the capability statement is front-loaded before the pricing note. Every clause carries information an agent needs.

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 3-parameter, no-output-schema tool, the description covers what it does, what comes back (answers with TTLs), and what it costs, while the schema carries the payment handshake. It falls just short on error/NXDOMAIN semantics and on any hint about naming conventions for the 'name' input.

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 100%, so the baseline is 3, but the description adds genuine meaning: it enumerates the nine supported record types (A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, SRV) that the schema only labels as 'Record type' with no enum. That closure of the value space is a real contribution; the paymentProof flow is left to the schema, which already documents it fully.

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 (resolves) and resource (DNS records), enumerates exactly which record types are supported, and names the transport (DNS-over-HTTPS). This clearly separates it from siblings like whois, http_check, and domain_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?

There is no when-to-use guidance and no routing to alternatives, despite several adjacent siblings (whois, domain_email_security, http_check) that an agent could plausibly confuse with this one. The only contextual signal is the price, which is a cost note rather than usage guidance.

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