[BUG] mcp__ide__getDiagnostics available in CLI (integrated terminal) but missing from VSCode extension panel

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Summary

mcp__ide__getDiagnostics is available when running Claude Code CLI from VSCode's integrated terminal, but is completely absent from the deferred tools list when running via the native VSCode extension panel. The entire ide MCP namespace is missing.

What Should Happen?

mcp__ide__getDiagnostics should be available in the extension panel, since the IDE MCP server is started by the extension itself.

Error Messages/Logs

try listing mcp__ide available pls

> Nothing. The mcp__ide__* namespace simply doesn't exist in this session's tool registry. Confirmed still broken.


[info] From claude: 2026-03-30T02:28:04.977Z [DEBUG] ToolSearchTool: keyword search for "ide diagnostics", found 0 matches

Steps to Reproduce

1. Open a TypeScript project in VSCode with the Claude Code extension active
2. Open the Claude Code extension panel
3. Ask Claude to use mcp__ide__getDiagnostics — tool is not available
4. The ide MCP namespace is entirely absent from the deferred tools list
5. Open VSCode's integrated terminal and run claude CLI
6. mcp__ide__getDiagnostics is available and works correctly

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.87

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

The IDE MCP server IS running (confirmed via lock file):

$ ls -t ~/.claude/ide/*.lock | head -1
~/.claude/ide/17340.lock

$ cat ~/.claude/ide/17340.lock
{"pid":713,"workspaceFolders":["/Users/username/..."],
"ideName":"Visual Studio Code","transport":"ws",
"runningInWindows":false,"authToken":"..."}

The extension panel knows it's running inside VSCode:

CLAUDE_CODE_ENTRYPOINT=claude-vscode
CLAUDECODE=1
CLAUDE_AGENT_SDK_VERSION=0.2.87

But it does not set the two env vars needed for IDE MCP server discovery:

ENABLE_IDE_INTEGRATION=   (empty)
CLAUDE_CODE_SSE_PORT=     (empty)

These env vars are only injected into integrated terminal contexts. The CLI in the terminal picks them up and connects to the IDE MCP server; the extension panel cannot discover it.

Workarounds attempted

| Approach | Result |
|---|---|
| claude-code.claudeProcessWrapper shell script that reads lock file and exports env vars | Env vars did not propagate — extension panel likely doesn't use the wrapper |
| mcp__ide__* explicitly allowed in .claude/settings.json and .claude/settings.local.json | No effect — tools are never registered |
| VSCode window reload | No effect |
| settings.json env field | Only accepts static strings; port is dynamic per session |

Working workaround

Use Claude CLI from VSCode's integrated terminal instead of the extension panel.

Additional context

• Other MCP servers work in the extension panel (mcp__chakra-ui__*, mcp__plugin_playwright_playwright__*, mcp__zeplin__*)
• The typescript-lsp plugin's LSP tool works correctly in the extension panel
• No PreToolUse hooks block mcp__ide__* tools
• No .mcp.json config exists