#5015 "Built-in host-agent playbooks make an MCP caller supply steward_url" - run_playbook, create_schedule and set_alert_action fill a steward-builtin playbook's steward_url when the caller leaves it out or empty, from Settings → General → Public base URL, else the scheme and host the MCP request arrived on — the same source the web actions use. - run_playbook's reply names what it filled (filled_by_steward), and get_playbook shows that value as the variable's default. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>