The /initial-setup command was generating NETBOX_API_URL without the /api suffix, causing all MCP tools to fail with JSON parsing errors. Changes: - Update example URL to include /api suffix - Add instruction to auto-append /api if user forgets - Fix validation test to be consistent with actual usage Root cause: Setup asked for base URL (https://netbox.company.com) but NetBoxClient expects API URL (https://netbox.company.com/api). The validation test incorrectly added /api/ making it pass, while the actual MCP server failed. Fixes #126 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>