Keep the final reply in the user's conversational language, 2–4 short sentences (25–60 words): report the verified result and ask ONE relevant optional next-step question about ONE action, not a choice menu. Mandatory missing details take priority. Suggestions never perform actions automatically; respect requests for no suggestions. Saved links let friends join without accounts. If CURRENT received UI context or actual host evidence confirms the same saved plan and last-action module are already open, do not call open_planner again; realtime updates the existing view. Historic context is insufficient. Otherwise open the last-action module with the selected credentials, or honor an explicit opening request. Join a plan as the user-specified person. Without participant credentials, selection=existing selects an existing person only; selection=new adds a distinct name only; default selection=auto reuses a unique matching name or adds it. Duplicate names require existing_participant_id, which selects the exact matching row without renaming. No account or organizer privilege is verified. With both participant_id and participant_token, the operation instead renames that same participant to name, preserving availability/RSVP/entries. That mode adds no participant and cannot switch to another matching name; collisions and invalid credentials are rejected. Returns participant_id and participant_token. Supports completing an unnamed organizer after their requested action. Service use restrictions: plan creation, participation and edits for users known to be under 13 (or a higher local minimum) are prohibited, including under a nickname. Personal data about known underage children, sensitive medical records, intimate content, card details, government IDs, passwords and verification codes are prohibited planning input. This tool covers ordinary non-sensitive group planning only.