# preflight_check

Answer 'is this cluster safe to launch on?' BEFORE you burn GPU-hours on a job that will die in the first ten minutes. Feed it the health artifacts from the nodes you are about to use — nvidia-smi -q, ibstat, nvidia-smi topo -m, dmesg -T — and it returns the critical blockers (dead links, missing GPUs, non-NVLink topology, driver mismatch) that would take the run down. Scale+ feature.

Agent View of the PolicyLayer registry record for `preflight_check`. HTML page: https://policylayer.com/tools/denpex-mcp/preflight-check

## Facts

- Tool: `preflight_check`
- Server: Denpex (`denpex-mcp`) — https://policylayer.com/tools/denpex-mcp.md
- Install: `npx -y denpex-mcp`
- Homepage: https://www.npmjs.com/package/denpex-mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 3
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `dir` | string | no | Directory to scan for the newest artifact file. |
| `file` | string | no | Path to a file containing them. |
| `logs` | string | no | Paste the health artifacts (nvidia-smi -q, ibstat, nvidia-smi topo -m, dmesg -T). |

Parameters from the server's own tool schema.

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

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

## Why preflight_check is rated Low

Even though preflight_check only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

Risk signals: Accepts file system path (file)

## Use case

AI agents call preflight_check to retrieve information from Denpex 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 Denpex:

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

## Other tools on Denpex (14)

- `compare_runs` — Execute — https://policylayer.com/tools/denpex-mcp/compare-runs.md
- `diff_environments` — Execute — https://policylayer.com/tools/denpex-mcp/diff-environments.md
- `node_health` — Execute — https://policylayer.com/tools/denpex-mcp/node-health.md
- `predict_failures` — Execute — https://policylayer.com/tools/denpex-mcp/predict-failures.md
- `analyze_cascade` — Read — https://policylayer.com/tools/denpex-mcp/analyze-cascade.md
- `ask_followup` — Read — https://policylayer.com/tools/denpex-mcp/ask-followup.md
- `check_quota` — Read — https://policylayer.com/tools/denpex-mcp/check-quota.md
- `check_versions` — Read — https://policylayer.com/tools/denpex-mcp/check-versions.md
- `diagnose_crash` — Read — https://policylayer.com/tools/denpex-mcp/diagnose-crash.md
- `list_incidents` — Read — https://policylayer.com/tools/denpex-mcp/list-incidents.md
- `lookup_failure` — Read — https://policylayer.com/tools/denpex-mcp/lookup-failure.md
- `recent_diagnoses` — Read — https://policylayer.com/tools/denpex-mcp/recent-diagnoses.md
- `validate_checkpoint` — Read — https://policylayer.com/tools/denpex-mcp/validate-checkpoint.md
- `submit_fix_outcome` — Write — https://policylayer.com/tools/denpex-mcp/submit-fix-outcome.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=denpex-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/denpex-mcp