Free public API. Look up the DKIM record at ._domainkey., parse the public key, flag issues.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Domain to check DKIM for. | |
| selector | Yes | DKIM selector — `google`, `k1`, `mxvault`, `s1`, etc. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds value by mentioning that it parses the public key and flags issues, but it does not disclose specifics like rate limits, response format details, or the meaning of 'flag issues'. The safety profile is covered by annotations, so a mid-range score is appropriate.
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?
The description is two succinct sentences with no filler. The first sentence states the resource and action, the second adds the parsing and issue-flagging behavior. Every word serves a purpose.
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 simple read-only API tool with no output schema, the description provides the core behavior (lookup, parse, flag) and the record path. It lacks explicit error handling or result format details, but the openWorldHint and simplicity of the tool make this sufficient.
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?
With 100% schema coverage, the baseline is 3. The description enhances this by specifying the exact DNS record format `<selector>._domainkey.<domain>`, which clarifies how the two parameters combine. This goes beyond the schema's simple field descriptions.
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 clearly states the tool looks up a DKIM record at `selector._domainkey.domain`, parses the public key, and flags issues. This specific verb+resource combination distinguishes it from sibling DNS tools like CNAME lookup or SPF record checker.
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 implies usage by explicitly describing the lookup pattern and parsing behavior. It does not explicitly exclude alternatives or name sibling tools, but the scope is clear enough for an agent to know when to select it over other DNS record checkers.
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.
