Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add dnsdoctor/claude-plugin --skill verify-changegit clone --depth 1 https://github.com/dnsdoctor/claude-pluginWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/dnsdoctor/claude-plugin/verify-change)<a href="https://agentmods.dev/skills/dnsdoctor/claude-plugin/verify-change"><img src="https://agentmods.dev/badge/skills/dnsdoctor/claude-plugin/verify-change/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/dnsdoctor/claude-plugin/verify-change"><img src="https://agentmods.dev/badge/skills/dnsdoctor/claude-plugin/verify-change.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00088 | $0.05183 |
| Opus 5.5 | $0.00035 | $0.02073 |
| Sonnet 5.5 | $0.00018 | $0.01037 |
| Haiku 4.5 | $0.00009 | $0.00518 |
Grade B, and why
verify-change scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Strips warnings and disclaimersmediumAnti-refusal
Omitting safety caveats hides risk from the user and is a common jailbreak preamble.
signature that proves the mail is really yours)"), and don't lecture or scare. This is a copy
91% identical to fix-dmarc — 95 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 268 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Verify a DNS change
The user changed a record and wants to know it worked. Three reads, in order, each ending on the next one. Stop when the user's question is answered.
Rules
- Observation only. No record is ever composed here. If the user needs a record, it comes from a DNS Doctor tool result, printed verbatim.
- An empty answer is absence; a lookup failure (
cant_tell,transient,unavailable) is unknown, never "the record is missing". - SPF is diagnose-only: if the SPF read looks wrong, relay what was found and never propose an SPF edit of your own.
- Plain words for a non-expert: see "Explain it for a non-expert" at the end of this skill.
Flow
- Did it land? Call
check_recordwith the domain, thekind(spf,dmarc,txt,mx,cname,a,aaaa),hostfor a label such asselector1._domainkeyorwww(txt, cname, a and aaaa only), andexpected_valueset to the value they published (exactly as they gave it, or as the tool that issued it returned it). Relayverdict:done: their nameservers serve it and both caches agree. End with: "Want me to check it has reached every region?" and, on yes, go to step 2.wait: it is published, caches are still catching up. Say when to look again (check_again_after_seconds, said in minutes) and end with: "Tell me then and I'll check again."edit: their nameservers do not serve it. Iffound_atnames another place, say the value was published there instead (often the domain typed twice in the host field). End with: "Fix that, then tell me and I'll check again."not_registered: true: the domain does not exist (usually a typo). Ask which domain they meant. Two resolvers is the whole sample of this read: never call it worldwide.
- Has it propagated? Call
check_propagationwith the exact name the record lives at (_dmarc.example.comfor DMARC,selector._domainkey.example.comfor DKIM, the apex for SPF and MX),record_type(TXTfor SPF, DMARC and DKIM), and the sameexpected_value. You have one network vantage point; this reads six. Reportvantage_reachedofvantage_total. Anunavailablecell is a probe that did not answer, never absence there. Averdictofunknownmeans coverage was too thin to call: say so, never round it up. If some regions still show the old value, end with when to look again (the record's TTL) and "tell me then and I'll check again". - Confirm the effect. When the change was a fix from a DNS Doctor scan,
once step 1 says
donecallscan_domainagain and say whether the check now passes. When it was a DNS Doctor verification record, callcheck_domain_verificationinstead.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 268 lines · 88 tokens per session scan B 031a20964ecc
verify-change is a skill published in the GitHub repository dnsdoctor/claude-plugin (3 stars, last pushed yesterday), licensed Apache-2.0. It adds 88 tokens to every session and 5,183 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it B with 1 finding (strips warnings and disclaimers). It is 91% identical to fix-dmarc, differing in 95 lines, and is treated as a copy.
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