Free public API. Query the same hostname across ~10 public DNS resolvers worldwide and report which ones return the same answer. Useful right after a DNS change.
| Name | Required | Description | Default |
|---|---|---|---|
| host | Yes | Hostname to check. | |
| type | No | Record type. Default: A. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/openWorld/idempotent, and the description aligns. It adds meaningful behavioral context: free public API (auth expectations), scale (~10 resolvers worldwide), and comparison logic. No contradiction; could have mentioned rate limits or output format but not necessary given annotations.
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 short front-loaded sentences; no filler. 'Free public API' is useful context, followed by what it does and when to use. Every sentence earns its place.
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?
Tool is simple (2 params, no nested, no output schema), and annotations cover safety. Description explains purpose, use case, and approximate behavior. Lacking explicit output format/fields, but for a public DNS checker the description is reasonably complete.
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 has 100% description coverage, so baseline is 3. The description reinforces 'host' as hostname and implies record type via 'DNS change' but adds no syntax or formatting beyond schema. It doesn't explain how 'type' affects the comparison.
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 uses a specific verb ('Query') and identifies the resource ('same hostname across ~10 public DNS resolvers worldwide'), clearly distinguishing it from sibling tools like dns_record_lookup or cname_lookup. The result behavior ('report which ones return the same answer') clarifies the propagation-checking purpose.
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 states when to use: 'Useful right after a DNS change.' Provides clear context but does not name alternatives or exclusions; with ~15 sibling DNS tools, an explicit 'use dns_record_lookup for a single resolver' would have been stronger.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Multiple tools operate in the same DNS/domain space, e.g., generic DNS record lookup overlaps with specific CNAME, TXT, SPF, DKIM, and DMARC lookups. Website status checker also overlaps with SSL check and redirect checker, though descriptions clarify their distinct purposes.
All tool names follow a consistent snake_case pattern with a 'tools_' prefix and an action word at the end (lookup, checker, check, finder). This makes the naming highly predictable and uniform.
16 tools is slightly above the ideal 3-15 range, but the domain intelligence scope is broad enough that each tool addresses a specific need without feeling bloated. The count is reasonable for a comprehensive domain/DNS toolkit.
The tool set covers a wide range of domain-related functionality: DNS records, email authentication (SPF, DKIM, DMARC), SSL/TLS, HTTP headers, redirects, WHOIS, availability, subdomain enumeration, and website status. No obvious critical gaps exist for its apparent purpose.
