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 allemaar/open-skills --skill domain-checkgit clone --depth 1 https://github.com/allemaar/open-skillsWrote 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/allemaar/open-skills/domain-check)<a href="https://agentmods.dev/skills/allemaar/open-skills/domain-check"><img src="https://agentmods.dev/badge/skills/allemaar/open-skills/domain-check/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/allemaar/open-skills/domain-check"><img src="https://agentmods.dev/badge/skills/allemaar/open-skills/domain-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 69 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 | $0.00144 | $0.02591 |
| Opus 5 | $0.00072 | $0.01295 |
| Sonnet 5 | $0.00029 | $0.00518 |
| Haiku 4.5 | $0.00014 | $0.00259 |
Grade A, and why
domain-check scanned grade A 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 11d ago.
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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
`curl` and `nslookup`. What none of them handle is **aftermarket detection** How it starts
The opening of the file, as written. The whole thing — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/domain-check
Availability tools disagree, and the one most people reach for is the one most likely to be wrong. This skill is a reconciliation policy, not another lookup client. It says which source wins when two sources conflict, what a negative result does and does not prove, and what the handler still does not know when the verdict lands.
The house rule is wrap, don't build. Keyless servers already implement
lookup with sensible fallbacks — saidutt46/domain-check and
stucchi/domain-check-mcp both do RDAP with a WHOIS fallback, and Brave Labs'
domain-checker-mcp ships a DNS-then-RDAP hybrid. Use one of those, or plain
curl and nslookup. What none of them handle is aftermarket detection
and a documented precedence order. That gap is this skill.
Structured execution spec:
protocol.yon. Read it for the canonical rules and step sequence; this file is explanation. The two must stay in sync — if you edit one, update the other and refresh the@STAMPdate.
Why this exists
A GoDaddy-backed availability tool reported available: true for seven
domains: hexis.com, shim.com, mortise.com, limen.com, vinculum.com,
honeyourcraft.com and poweryouragent.com. Every one was registered and
parked on a broker nameserver — afternic.com, namefind.com, or
domainmarket.com.
The failure was confirmed independently. A request to
https://rdap.verisign.com/com/v1/domain/hexis.com returns HTTP 200, meaning
registered. A genuinely unregistered domain and a random control both return
404. So RDAP was right, DNS was right, and the registrar layer was the
unreliable one.
A hypothesis, not a diagnosis. GoDaddy's availability endpoint takes a
checkType parameter of FAST (the default) or FULL, documented as
"Optimize for time (FAST) or accuracy (FULL)". It also returns a definitive
boolean meaning the answer was verified against the registry. A tool sitting on
the default fast path would plausibly produce exactly these false positives.
That fits the evidence. It has not been confirmed against a live trace, and
this skill does not assert it as the cause.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 11d ago First seen · 213 lines · 144 tokens per session scan A 869c950d275b
domain-check is a skill published in the GitHub repository allemaar/open-skills (14 stars, last pushed yesterday), licensed Apache-2.0. It adds 144 tokens to every session and 2,591 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
polis-protocol
Set up and run a self-improving, multi-vendor AI agent team with the Polis Protocol — a markdown polis/ folder where each agent is a citizen with a capability card, tasks are contracts routed to whoever has the best track record by a learning router, settled work files lessons that compound into team memory, and…
media
Skill "media" from ymxlx/polis-protocol, covering polis protocol: a self-optimizing city of agents, the core idea, when this skill is active, structure of a polis and the first thing to do every session.
_data
Skill "_data" from ymxlx/polis-protocol, covering polis protocol: a self-optimizing city of agents, the core idea, when this skill is active, structure of a polis and the first thing to do every session.
subagent-driven-development
Execute plans via delegatetask subagents (2-stage review).
mcporter
List, auth, and call MCP servers/tools from the terminal.
research-engineer
An uncompromising Academic Research Engineer. Operates with absolute scientific rigor, objective criticism, and zero flair. Focuses on theoretical correctness, formal verification, and optimal implementation across any required technology.