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

With no annotations, the description carries the full burden, and it does meaningful work: it discloses that lookups use the system resolver (not authoritative queries), that only public records are returned, and that each call costs $0.001 USDC on Base via x402 – a paid-call disclosure an agent must know before invoking. It omits failure behavior and default-type handling.

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: purpose first, capabilities second, cost last. Every sentence carries information an agent needs and there is no filler.

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 two-parameter read tool with no output schema or annotations, the description covers purpose, record-type scope, resolver choice and payment requirement. The remaining gap is default behavior when 'type' is omitted and any error/empty-result semantics.

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. It equates 'host' with a hostname and restates the nine record types that the enum already lists, but it never explains the effect of omitting the optional 'type' parameter (default record type, or all types), which is the main semantic 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 specific verb and resource ('Resolve public DNS records for a hostname') and enumerates exactly which record types are supported, so an agent knows the exact scope. No sibling tool overlaps with DNS resolution, so no differentiation is needed.

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?

Usage is implied – resolving DNS for a hostname is self-explanatory and no alternative tool exists in the sibling list. However, there is no explicit when-to-use framing, no statement of prerequisites (network availability, payment balance), and no guidance on choosing a record type or whether omitting 'type' is valid.

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