check_ns

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

Annotations already declare readOnlyHint and idempotentHint. The description adds behavioral context: identifies provider, shows delegation and redundancy. However, it does not disclose caching behavior or how 'auto-detected' format works, though output schema exists.

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?

Four concise sentences front-loading purpose and use case. No wasted words, and each sentence adds distinct value.

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 the tool's simplicity, annotations covering safety, and presence of output schema, the description is complete. It provides the essential 'why' and 'part of audit' context, sufficient for agent invocation.

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?

Input schema covers all 3 parameters with descriptions (100% coverage). The description adds general context about the check's output but does not enrich parameter semantics beyond what's in the schema.

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 explicitly states it looks up NS records, identifies the DNS nameserver provider (Cloudflare, Route53, etc.), and shows delegation and redundancy. It clearly distinguishes from sibling tools like check_mx or check_dkim by specifying 'NS records'.

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?

The description provides a clear use case: 'Use to find out which authoritative nameserver or DNS hosting service is used for a domain.' It also mentions being part of scan_domain audit, but lacks explicit guidance on when not to use this tool instead of broader alternatives like scan_domain.

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