Like bahnrider said there is no point in buying an OV Chipkaart for such small trips. At least for the train rides you're better off buying tickets (issued at disposable chip-cards) from the vending machines at the railway stations.
For transport within the cities that you plan to visit the specialist tourist offerings could be worth your money. These come on disposable chip-cards and can be bought at railway stations, tourist offices, sometimes on board of the bus or tram, and some hotels sell these at the reception.
For the Amsterdam region the Amsterdam and Region Travel Ticket covers Haarlem, Amsterdam as well as the bus between Schiphol and Haarlem (bus 300 runs every 5 minutes or so - if you don't choose to use Uber after all). It also covers some train lines as shown on the map linked on this site: Amsterdam & Region Travel Ticket | I amsterdam . But indeed it does not cover trains to The Hague.
Various products exist in the South Holland province, check the full offering here: How does it work | Tourist Day Ticket (touristdaytickets.com). These are also issued on disposable chip-cards. A tourist ticket covering the full province costs €14,50. This ticket does NOT cover Dutch Railways (NS) trains, but it does cover the metro line between The Hague and Rotterdam.
Finally, a day pass the for The Netherlands complete exist. This covers all forms of public transport, including all trains. The cheapest option (off-peak) is €43, but only rarely is this pass more economical than buying loose tickets (Holland Travel Ticket | Tickets & Supplements | NS)
Finally, for planning your journeys it's efficient to use www.9292ov.nl., it covers all forms of public transport in the Netherlands. They also have an app that you can download on your smartphone.