The Hilton is in a office only part of the city, where there is nothing to do or eat close by. The subway station is quite far, even if you have an entrance nearby it requires walking quite a bit in the tunnels.
I would look at a japanese chain in an area like Asakusa or Kanda, they will have plenty of food options and very easy access to pretty much everything. Roppongi, Shibuya and Shinjuku (leisure side) are very noisy and crowded, too much with a toddler. Chain wise I like Dormy Inn which have free ramen, ice cream and onsen.