[BUG] Agent Teams tools (TeammateTool, SendMessage, spawnTeam) not available in VS Code extension despite CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1

Description

Agent Teams tools are not available in the VS Code extension despite having CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1 configured in settings.json. The system prompt explicitly states "The 'Agent Teams' feature (TeammateTool, SendMessage, spawnTeam) is not available on this plan" even on an Enterprise plan.

Environment

• Claude Code Version: 2.1.50
• Platform: macOS (Darwin 25.2.0)
• IDE: VS Code extension
• Plan: Enterprise (Algolia organization)
• Model: Claude Opus 4.5

Configuration

~/.claude/settings.json:
\\\json
{
"env": {
"CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS": "1"
},
"permissions": {
"allow": ["Bash(*)", "Read(*)", "Edit(*)", "Write(*)", ...],
"defaultMode": "acceptEdits"
},
"model": "opus"
}
\\\

Expected Behavior

With CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1 set and an Enterprise plan, the following tools should be available:

• TeammateTool (spawnTeam, cleanup)
• SendMessage (message, broadcast, shutdown_request/response)
• Task tool with team_name and name parameters

Actual Behavior

1. The Task tool schema only includes: description, max_turns, model, prompt, resume, run_in_background, subagent_type
2. Missing parameters: mode, team_name, name
3. TeammateTool, SendMessage, spawnTeam tools are not exposed
4. System prompt contains: "The 'Agent Teams' feature (TeammateTool, SendMessage, spawnTeam) is not available on this plan."

Root Cause Analysis

Based on research, the feature appears to be gated by internal functions I9() and qFB() in the minified JS. Setting the environment variable alone doesn't cause these functions to return true.

The workaround claude-sneakpeek (github.com/mikekelly/claude-sneakpeek) patches these functions for the CLI, but this doesn't help VS Code extension users.

Impact

Without Agent Teams, users must rely on Task tool subagents which:

• Share the parent's context window (causing frequent context compaction)
• Cannot communicate peer-to-peer
• Cannot coordinate via shared task boards

This significantly impacts complex workflows like multi-agent research tasks where context isolation is critical.

Related Issues

• #25254 - Team agents' messages not delivered to team lead in VS Code extension
• #25520 - VS Code extension doesn't show permission prompts from background agent team members
• #25148 - Feature Request: Enable Agent Teams on all plans

Request

Please either:

1. Enable Agent Teams tools in VS Code extension when CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1 is set
2. Or provide clear documentation on what's required to enable these tools (if plan-gated, specify which plans)

Workaround Attempted

• Installed claude-sneakpeek - but this only works for CLI, not VS Code extension
• Tried various permission configurations - no effect
• Restarted VS Code multiple times - no effect