[Feature Request] Allow skills to hide underlying MCP tools from Claude (progressive disclosure)

Problem

Skills cannot hide their underlying MCP tools from Claude's direct access. Both the skill wrapper and the raw MCP tool are visible, defeating progressive disclosure.

Requested Feature

Add configuration to hide MCP tools from Claude's tool list while still allowing skills to use them internally.

Proposed syntax (.claude/settings.json):

{
  "mcpServers": {
    "tts": {
      "toolVisibility": {
        "mcp__tts__synthesize_speech": "skill-only"
      }
    }
  }
}

Benefits

• Progressive disclosure: Show Claude only high-level skill interfaces, hide low-level tool complexity
• Cleaner tool lists: Reduce cognitive load when working with many MCP tools
• Better abstractions: Skills can provide curated, project-specific interfaces to generic tools

Use Case

Wrapping 100+ AWS MCP tools with a few high-level deployment skills (deploy-staging, deploy-production) while hiding the raw mcp__aws__* tools from Claude's direct access.