# check_dkim

Check whether a DKIM public key is published for a domain and selector. Looks up the TXT record at selector._domainkey.domain. selector: DKIM selector name (e.g. 'google', 'mail', 'default', 's1'). nameserver: optional custom resolver IP.

Agent View of the PolicyLayer registry record for `check_dkim`. HTML page: https://policylayer.com/tools/aaronckj-mcp-nettools/check-dkim

## Facts

- Tool: `check_dkim`
- Server: Mcp Nettools (`aaronckj/mcp-nettools`) — https://policylayer.com/tools/aaronckj-mcp-nettools.md
- Homepage: https://github.com/aaronckj/mcp-nettools
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "check_dkim",
    "arguments": {}
  }
}
```

## Why check_dkim is rated Low

This is a read-only network diagnostic tool that retrieves published DKIM configuration data from DNS. It only queries information that is already publicly available via DNS TXT records and does not modify, execute, or delete anything. The blast radius of misuse is minimal - an attacker could enumerate DKIM configurations across domains, but cannot alter them or cause direct harm.

From the tool's own definition: "Tool performs DNS TXT record lookup ('Looks up the TXT record') for DKIM public key verification. No modification, deletion, or execution of code/commands occurs. The operation is a pure query with no side effects."

## Use case

AI agents call check_dkim to retrieve information from Mcp Nettools without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mcp Nettools:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "check_dkim": {}
  }
}
```

## Other tools on Mcp Nettools (234)

- `http_delete` — Destructive — https://policylayer.com/tools/aaronckj-mcp-nettools/http-delete.md
- `check_mqtt` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/check-mqtt.md
- `check_rdp` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/check-rdp.md
- `http_post` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/http-post.md
- `ping` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/ping.md
- `port_scan` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/port-scan.md
- `speedtest` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/speedtest.md
- `traceroute` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/traceroute.md
- `wake_on_lan` — Execute — https://policylayer.com/tools/aaronckj-mcp-nettools/wake-on-lan.md
- `arp_table` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/arp-table.md
- `bgp_lookup` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/bgp-lookup.md
- `cert_check` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/cert-check.md
- `cert_check_bulk` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/cert-check-bulk.md
- `check_actual_budget` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-actual-budget.md
- `check_adguard` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-adguard.md
- `check_alertmanager` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-alertmanager.md
- `check_anythingllm` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-anythingllm.md
- `check_appwrite` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-appwrite.md
- `check_archivebox` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-archivebox.md
- `check_audiobookshelf` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-audiobookshelf.md
- `check_authelia` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-authelia.md
- `check_authentik` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-authentik.md
- `check_baikal` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-baikal.md
- `check_bazarr` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-bazarr.md
- `check_beszel` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-beszel.md
- `check_bitwarden` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-bitwarden.md
- `check_bookstack` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-bookstack.md
- `check_calibre_web` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-calibre-web.md
- `check_cassandra` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-cassandra.md
- `check_changedetection` — Read — https://policylayer.com/tools/aaronckj-mcp-nettools/check-changedetection.md
- …and 204 more: https://policylayer.com/tools/aaronckj-mcp-nettools.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=aaronckj-mcp-nettools · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/aaronckj-mcp-nettools