[BUG] Bug: Teammates do NOT load skills despite documentation stating they do

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?

Description

The agent teams documentation states:

"Each teammate has its own context window. When spawned, a teammate loads the same project context as a regular session: CLAUDE.md, MCP servers, and skills."

In practice, teammates have zero access to skills:

• The Skill tool is not in their toolset
• No skill definitions appear in their system context
• No skill-related system-reminder blocks are visible
• They cannot invoke any skill by name
• Adding Skill to the agent definition's tools list has no effect

Teammate's actual toolset

Read, Edit, Write, Bash, Glob, Grep, TaskCreate, TaskUpdate, TaskGet, TaskList, SendMessage

11 tools total. No Skill tool. Compare to the main session which has Skill and sees 100+ skill definitions.

Testing performed

Tested 4 times across different configurations:

| Test | Configuration | Result |
|------|--------------|--------|
| 1 | Sub-agent, Skill added to agent MD tools list | No Skill tool available |
| 2 | Teammate (with team_name), default tools | No Skill tool available |
| 3 | Teammate, asked to search for any skill-related content in context | Zero skills visible |
| 4 | Teammate, Skill in agent MD tools list + explicit instruction to invoke | No Skill tool in runtime |

Each time the teammate was asked to list all available tools and report any skill-related content. All 4 tests returned the same result: no Skill tool, no skill definitions visible.

4. Teammate will report: No Skill tool, no skills visible

### Impact

Without skills, all specialized knowledge must be embedded directly into agent MD files. This:
- Bloats agent definitions (ours are 400-800 lines each, and growing)
- Makes maintenance harder (60+ agent files to update when adding a new capability)
- Prevents modular knowledge sharing (skills are the designed mechanism for this)
- Forces workarounds like embedding bash command templates in agent MDs

### Environment

- Claude Code: Latest (Claude Opus 4.6)
- OS: Windows 11
- Skills directory: `~/.claude/skills/` (100+ skills defined and working in main session)
- Agent count: 60+ custom agents in `.claude/agents/`
- Testing: Both sub-agents and teammates tested

### What Should Happen?

### Expected behavior

Per documentation, teammates should load skills as part of their project context. This means:
- The `Skill` tool should be available in the teammate's toolset
- Skill definitions (from `~/.claude/skills/`) should be visible in the teammate's context
- Teammates should be able to invoke skills by name

### Error Messages/Logs

```shell

Steps to Reproduce

Reproduction steps

# 1. Create a skill at ~/.claude/skills/my-skill/SKILL.md
# (any valid skill definition)

# 2. Verify the main session can see it
# Main session will list it in system-reminder blocks and can invoke via Skill tool

# 3. Create a team and spawn a teammate
TeamCreate(team_name="test", description="Skill test")

Task(
    subagent_type="My-Agent",       # Any custom agent from .claude/agents/
    name="my-agent",
    team_name="test",
    prompt="List ALL your tools. Do you see any skills? Try to invoke Skill(skill='my-skill')."
)


### Claude Model

Opus

### Is this a regression?

No, this never worked

### Last Working Version

_No response_

### Claude Code Version

2.1.38

### Platform

Anthropic API

### Operating System

Windows

### Terminal/Shell

PowerShell

### Additional Information

_No response_