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

With no annotations, the description carries the full burden. It does add real context beyond the name — the Cloudflare 1.1.1.1 DoH backend and the 'default: all' type behavior — but says nothing about whether the operation is purely read-only, how failures (NXDOMAIN, timeouts, rate limits) surface, or what the response contains.

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 compact sentences with zero filler; the operation and backend come first, followed immediately by the parameter detail. Nothing is padded or repeated.

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?

There is no output schema and no annotations, so the description is the only source of behavioral information — yet it never describes the return shape (records, answers, TTLs) or error behavior. For a network lookup tool this leaves a meaningful gap.

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 fully documents the 'types' parameter (allowed values plus default), though the schema enum already lists those values. The required 'domain' parameter gets no format guidance at all — subdomains, trailing dots, or IDN handling are unaddressed.

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 gives a specific verb and resource ('Resolve DNS records for a domain') and even names the resolver backend. It implicitly distinguishes itself from siblings like lookup_ip and reverse_dns by operating on a domain name, but never explicitly brackets what this tool is not for.

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 by the purpose statement — an agent can infer this is the tool for forward DNS resolution on a domain — but there is no explicit when-to-use or when-not-to-use guidance and no mention of alternatives such as reverse_dns or whois_lookup for adjacent lookups.

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