# compare_runs

'It worked yesterday.' Give it the logs from the run that worked and the run that failed, and it isolates what actually changed between them instead of re-diagnosing the failure from scratch. Use this whenever a previously-green job starts failing.

Agent View of the PolicyLayer registry record for `compare_runs`. HTML page: https://policylayer.com/tools/denpex-mcp/compare-runs

## Facts

- Tool: `compare_runs`
- 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: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 2 (2 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `failLogs` | string | yes | Logs from the run that failed. |
| `successLogs` | string | yes | Logs from the run that worked. |

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": "compare_runs",
    "arguments": {
      "failLogs": "<failLogs>",
      "successLogs": "<successLogs>"
    }
  }
}
```

## Why compare_runs is rated High

compare_runs triggers real processes with real consequences. An agent gone sideways doesn't fire it once. It starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.

## Use case

AI agents invoke compare_runs to trigger actions in Denpex. 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 Denpex:

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

## Other tools on Denpex (14)

- `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
- `preflight_check` — Read — https://policylayer.com/tools/denpex-mcp/preflight-check.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