The best place to find an answer to this question is Chapter 13. There, Diamond gives two reasons why agriculture leads to the development of technology.
The first reason comes from the fact that agriculture generally makes people stay in one place rather than roaming nomadically. When this happened, people could accumulate more possessions since they didn't have to carry them everywhere with them. They could then have more of a use for technologies (Diamond gives the example of a loom) that were not portable.
The second reason comes from the fact that agriculture makes more food available. Farmers can produce enough to feed themselves and their families and still have a surplus. This surplus can feed specialists who can do things like creating and using technology.
In these two ways, agriculture leads (Diamond says) to the development of technology.