As you look for an agent, you will likely find at some point that an agent will ask for an exclusive look. That means they want to be able to read the manuscript and consider representing you without any other agent reading the manuscript at the same time.
This is standard practice. Agents don’t want to spend time reading and falling in love with a work only to discover they lost you to the competition by a single day.
However, you have your own needs…and you don’t want to wait weeks or months for the agent to respond.
When you are asked for an exclusive, set a timeframe. Tell them yes then ask if two weeks is enough time. It’s very likely they will ask for three weeks. But if you offer three weeks they’ll ask for four. So set your own limit right from the start. Three weeks is plenty of time. And you’ll come off as a professional because you knew to set a time limit from the beginning!