# shell_exec

A execute tool on the Hercules MCP MCP server.

Agent View of the PolicyLayer registry record for `shell_exec`. HTML page: https://policylayer.com/tools/0xmihirk-hercules-mcp/shell-exec

## Facts

- Tool: `shell_exec`
- Server: Hercules MCP (`0xmihirk/hercules-mcp`) — https://policylayer.com/tools/0xmihirk-hercules-mcp.md
- Homepage: https://github.com/0xMihirK/hercules-mcp
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

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

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

## Why shell_exec is rated High

shell_exec executes shell commands whose effects are determined entirely by user input. In the context of a penetration testing tool, this permits running any command within the container—including reconnaissance, exploitation, lateral movement, and system compromise. Effects depend on arguments and are not reversible in some cases (e.g., file deletion, system modification).

From the tool's own definition: "Tool named 'shell_exec' with no description; context indicates it is part of a penetration testing framework exposing 'offensive security tools' in a Kali Linux container. The name 'shell_exec' directly indicates execution of arbitrary shell commands."

## Use case

AI agents invoke shell_exec 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.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Hercules MCP:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "shell_exec": {
      "limits": [
        {
          "counter": "shell_exec_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Hercules MCP (44)

- `browser_act` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/browser-act.md
- `browser_cmd` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/browser-cmd.md
- `browser_eval` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/browser-eval.md
- `browser_open` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/browser-open.md
- `browser_session` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/browser-session.md
- `browser_wait` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/browser-wait.md
- `bruteforce_hydra` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/bruteforce-hydra.md
- `crack_john` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/crack-john.md
- `ctf_binwalk` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/ctf-binwalk.md
- `ctf_steghide` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/ctf-steghide.md
- `fuzz_dirs` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/fuzz-dirs.md
- `metasploit_generate_payload` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/metasploit-generate-payload.md
- `metasploit_manage` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/metasploit-manage.md
- `metasploit_run_module` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/metasploit-run-module.md
- `metasploit_start_listener` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/metasploit-start-listener.md
- `ncat` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/ncat.md
- `network_curl` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/network-curl.md
- `network_hping3` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/network-hping3.md
- `nmap_run_nse_script` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/nmap-run-nse-script.md
- `nmap_scan` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/nmap-scan.md
- `nmap_write_nse_script` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/nmap-write-nse-script.md
- `nuclei_run` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/nuclei-run.md
- `recon_amass` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/recon-amass.md
- `recon_dns` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/recon-dns.md
- `searchsploit` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/searchsploit.md
- `shell_exec_background` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/shell-exec-background.md
- `shell_kill_job` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/shell-kill-job.md
- `sqlmap_run` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/sqlmap-run.md
- `system_start_new_session` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/system-start-new-session.md
- `system_stop_container` — Execute — https://policylayer.com/tools/0xmihirk-hercules-mcp/system-stop-container.md
- …and 14 more: https://policylayer.com/tools/0xmihirk-hercules-mcp.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=0xmihirk-hercules-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/0xmihirk-hercules-mcp