Tool for editing an existing task.
Parameters expected:
- •task_id (integer) or title (string)
- •title (string, optional) – new title
- •description (string, optional) – new description
Rules & behavior:
- •At least one field must be provided
- •Reply: "Task updated: new title '{new_title}'"
- •If no change: "Nothing to update."
- •If task not found: ask to list first