Claude Code reads mcpServers from ~/.claude.json (global state file),
NOT from ~/.claude/settings.json. The settings.json mcpServers key is
silently ignored for MCP loading. Using claude mcp add --scope user
writes to the correct file.
Also document correct registration commands and scope semantics in
RUNTIME.md so agents and users know how to add MCPs that actually load.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>