session-scoped-mcps-invisible-to-subagents-started-before-registration

Session-scoped MCP servers (claude mcp add -s project) registered mid-session are not visible to subagents that were dispatched before the registration occurred. Permanent user-scope servers (registered in ~/.claude.json top-level mcpServers) are always visible to all subagents. For tasks requiring a session-scoped MCP, register it before dispatching any subagent — or use a Bash-tool fallback. The 11 permanent MCPs cover the primary execution surface by design.