# performance_start_trace

Start a performance trace on the selected webpage. Use to find frontend performance issues, Core Web Vitals (LCP, INP, CLS), and improve page load speed.

Agent View of the PolicyLayer registry record for `performance_start_trace`. HTML page: https://policylayer.com/tools/async23-chrome-devtools-mcp/performance-start-trace

## Facts

- Tool: `performance_start_trace`
- Server: Chrome Devtools (`@async23/chrome-devtools-mcp`) — https://policylayer.com/tools/async23-chrome-devtools-mcp.md
- Install: `npx -y @async23/chrome-devtools-mcp`
- Homepage: https://github.com/Async23/chrome-devtools-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": "performance_start_trace",
    "arguments": {}
  }
}
```

## Why performance_start_trace is rated High

Starting a performance trace is an active operation that instruments and monitors a webpage, executing browser-level tracing logic. While not destructive or financial, it modifies the execution environment of the page and could be misused to extract sensitive timing data, trigger side effects during trace collection, or interfere with page functionality.

From the tool's own definition: "Tool description states 'Start a performance trace on the selected webpage' – this triggers external operations (Chrome DevTools tracing) that depend on runtime arguments and affects the target page's behavior."

## Use case

AI agents invoke performance_start_trace to trigger actions in Chrome Devtools. 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 Chrome Devtools:

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

## Other tools on Chrome Devtools (49)

- `close_heapsnapshot` — Destructive — https://policylayer.com/tools/async23-chrome-devtools-mcp/close-heapsnapshot.md
- `close_page` — Destructive — https://policylayer.com/tools/async23-chrome-devtools-mcp/close-page.md
- `uninstall_extension` — Destructive — https://policylayer.com/tools/async23-chrome-devtools-mcp/uninstall-extension.md
- `click` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/click.md
- `click_at` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/click-at.md
- `drag` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/drag.md
- `emulate` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/emulate.md
- `evaluate` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/evaluate.md
- `evaluate_script` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/evaluate-script.md
- `execute_3p_developer_tool` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/execute-3p-developer-tool.md
- `execute_webmcp_tool` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/execute-webmcp-tool.md
- `fill_form` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/fill-form.md
- `handle_dialog` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/handle-dialog.md
- `hover` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/hover.md
- `install_extension` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/install-extension.md
- `lighthouse_audit` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/lighthouse-audit.md
- `navigate` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/navigate.md
- `performance_stop_trace` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/performance-stop-trace.md
- `press_key` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/press-key.md
- `reload_extension` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/reload-extension.md
- `resize_page` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/resize-page.md
- `screencast_stop` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/screencast-stop.md
- `select_page` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/select-page.md
- `trigger_extension_action` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/trigger-extension-action.md
- `type_text` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/type-text.md
- `wait_for` — Execute — https://policylayer.com/tools/async23-chrome-devtools-mcp/wait-for.md
- `compare_heapsnapshots` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/compare-heapsnapshots.md
- `get_console_message` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/get-console-message.md
- `get_heapsnapshot_class_nodes` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/get-heapsnapshot-class-nodes.md
- `get_heapsnapshot_details` — Read — https://policylayer.com/tools/async23-chrome-devtools-mcp/get-heapsnapshot-details.md
- …and 19 more: https://policylayer.com/tools/async23-chrome-devtools-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`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=async23-chrome-devtools-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/async23-chrome-devtools-mcp