domain_fetch_dns_records

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

Despite no annotations, description discloses read-only, idempotent, no side effects, 4-hour cache, and specifies what to do if response doesn't serve need.

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?

Every sentence adds value; front-loaded with purpose; no fluff.

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?

Given output schema exists, description covers all important aspects: source, constraints, alternatives, and error handling.

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 0%, but description explains domain format and required record types with valid values and an example, fully compensating.

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?

Description clearly states 'Fetch current DNS records for a domain via Cloudflare DNS over HTTPS. Read-only. No side effects. Idempotent.' and explicitly distinguishes from sibling tool domain_fetch_domain_rdap.

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?

Explicitly says 'Use this when you need live DNS resolution' and 'Use domain_fetch_domain_rdap instead when you need registration metadata not DNS records.' Also mentions cache duration and source.

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