chrome-devtools MCP ignores user-specified command, args, and env configuration

Description

When using the chrome-devtools MCP server, Claude Code completely ignores the user-specified command, args, and env fields in the configuration. It always spawns npm exec chrome-devtools-mcp@latest with no additional arguments, regardless of what is configured.

This makes it impossible to run multiple Chrome DevTools MCP instances in parallel (e.g., across git worktrees), since every instance attempts to use the same default Chrome profile directory ($HOME/.cache/chrome-devtools-mcp/chrome-profile).

Steps to Reproduce

1. Configure chrome-devtools MCP in ~/.claude.json with custom --userDataDir:

{
  "projects": {
    "/path/to/worktree-1": {
      "mcpServers": {
        "chrome-devtools": {
          "command": "npx",
          "args": ["-y", "chrome-devtools-mcp@latest", "--userDataDir", "/custom/path/chrome-profile-wt1"],
          "env": {
            "HOME": "/custom/home"
          }
        }
      }
    }
  }
}

1. Start Claude Code in the worktree
2. Run /mcp to connect
3. Observe that the spawned process is always npm exec chrome-devtools-mcp@latest — without --userDataDir, without custom env

What Was Tried (All Ignored)

| Approach | Result |
|----------|--------|
| args with --userDataDir /path (separate args) | Ignored |
| args with --userDataDir=/path (= syntax) | Ignored |
| command set to sh, args ["-c", "npx -y chrome-devtools-mcp@latest --userDataDir /path"] | Ignored |
| command set to absolute path of a wrapper script | Ignored |
| Renaming MCP server key to chrome-devtools-wt1 | Ignored (still reconnects to chrome-devtools) |
| Adding env.HOME field | Ignored (HOME remains unchanged in process) |
| .mcp.json in project root with custom config | Ignored |

Verified by inspecting the actual spawned process:

$ ps aux | grep chrome-devtools-mcp | grep node
npm exec chrome-devtools-mcp@latest    # <-- no --userDataDir, no custom args

And checking the process environment:

$ ps eww -p <PID> | tr ' ' '\n' | grep "^HOME="
HOME=/Users/byron    # <-- not the custom HOME from env config

Expected Behavior

Claude Code should respect the user-specified command, args, and env fields for the chrome-devtools MCP server, the same way it does for other MCP servers. This would allow:

• Running multiple Chrome DevTools instances with separate --userDataDir paths
• Connecting to pre-launched Chrome via --browserUrl
• Using --isolated mode
• Any other chrome-devtools-mcp CLI options

Use Case

Running multiple Claude Code sessions in parallel using git worktrees, each needing its own Chrome DevTools browser instance for testing/verification. Currently, only one session can use chrome-devtools MCP at a time because all sessions fight over the same default Chrome profile.

Environment

• Claude Code version: latest (as of 2025-03-04)
• chrome-devtools-mcp: @latest via npx
• OS: macOS (Darwin 25.2.0)
• Node: v22.x, npm 10.9.0