Returns METADATA ONLY about a display's current content: active file name, currentContentDescription (a one-sentence summary, e.g. 'Italian bistro menu — Mittagskarte'), idle-content state, content version id, delivery state, last delivery timestamp. Does NOT return a visible preview. If the user asked anything that implies SEEING the screen ('was läuft', 'zeig mir das Display', 'show me my display', 'preview', 'what's on it'), call get_display_preview_url INSTEAD or IN ADDITION — that one returns a signed previewUrl the agentView widget renders inline. Use this tool's currentContentDescription as a one-line caption alongside the preview, not as a replacement. Use read_display_html only when raw HTML source access is truly needed (debugging, copy-paste). Requires content_only scope.