- Add bidirectional remapping for nested tool_references inside tool_search_tool_result across non-stream, SSE stream, and multi-turn message history. - Add advisor_ and agent_toolset_ to IsClaudeServerToolType to prevent schema stripping and MCP aliasing on native Anthropic server tools. - Wrap MCP alias restoration errors in claudeMCPAliasRestoreError with IsRequestScoped() bool to avoid cooling down healthy OAuth credentials. - Add unit tests for tool_search_tool_result remapping, error variants, server tool recognition, and error scoping.