recon_dns

Run DNS lookups with dig or bulk DNS resolution with dnsx.

SERVERHercules MCP SOURCE0xmihirk/hercules-mcp

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/0xmihirk-hercules-mcp/recon-dns.md

WHAT IT DOES

What recon_dns does on Hercules MCP

AI agents invoke recon_dns to trigger actions in Hercules MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

RISK

Why recon_dns is rated High

DNS reconnaissance (dig, dnsx) actively executes external network tools to probe and enumerate domain infrastructure. While DNS queries themselves are read-like in nature, the tool description emphasizes running/executing these commands, and in a penetration testing context, DNS recon is an offensive operation that triggers network probes whose scope and targets are argument-dependent.

From the tool's definition Tool description states 'Run DNS lookups with dig or bulk DNS resolution with dnsx' — explicitly executing external commands (dig, dnsx) whose effects depend on target arguments.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs recon_dns safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Hercules MCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For recon_dns, this is the rule to start with:

recon_dns Rate-limited

recon_dns stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "recon_dns": {
      "limits": [
        {
          "counter": "recon_dns_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Hercules MCP, apply this rule, and every recon_dns call is checked against it from then on.

FAQ

Questions about recon_dns

What does the recon_dns tool do? +

Run DNS lookups with dig or bulk DNS resolution with dnsx. It is categorised as a Execute tool in the Hercules MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on recon_dns? +

Register the Hercules MCP server in PolicyLayer and add a rule for recon_dns: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Hercules MCP. Nothing to install.

What risk level is recon_dns? +

recon_dns is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit recon_dns? +

Yes. Add a rate_limit block to the recon_dns rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block recon_dns completely? +

Set action: deny in the PolicyLayer policy for recon_dns. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides recon_dns? +

recon_dns is provided by the Hercules MCP server (0xmihirk/hercules-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Hercules, and thousands of servers like it.

This server

All 45 Hercules tools → High-risk tools on this server →

Across the catalogue

All high-risk MCP tools → The MCP Attack Database →

Guides

Govern code and CI agents →Agent sandbox →Least privilege for MCP →