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

Annotations already establish read-only, idempotent, open-world, non-destructive behavior, so the bar is lower. The description still adds real behavioral facts the annotations do not cover: the upstream resolver (Cloudflare DoH), a per-success charge of $0.005 USDC via x402 on Solana, and an equivalent HTTPS endpoint. It omits error/failure behavior and whether failed lookups are billed.

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 what the tool returns before the pricing and transport details. Every element — record list, resolver, price, alternate endpoint — is actionable information with 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 one-parameter, no-output-schema tool the description is nearly complete: it tells the agent what will come back (the record types) and what it will cost. The remaining gap is output shape — grouping, per-type errors, or absence of a record type — which the agent has no other source for.

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?

There is one required parameter with 0% schema description coverage, so the description must carry the semantics. Saying records are gathered 'for a domain' gives minimal context, but it never specifies accepted format (bare hostname vs. URL vs. subdomain) or whether record types can be filtered. Partial compensation only.

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 names the resource precisely (all common DNS records for a domain) and enumerates the exact record types returned (A, AAAA, NS, MX, TXT, CAA), so an agent can distinguish it from narrow siblings like mx_check or ct_subdomains. It stops short of naming those siblings explicitly, which keeps it from 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?

Usage is only implied: an agent can infer this is the tool for a full record sweep of a domain rather than a single record type. There is no explicit when-to-use/when-not and no routing to dns_propagation, mx_check, or domain_intel, which are the obvious alternatives.

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