Later in the article it points out that you need to punch holes in your sandbox in order to train the models - because the wheels exercises they are are training on need tools and data from outside that sandbox.

> Agents are most useful when they have access to information. That data can be drawn live from the Internet, which is fundamentally a two-way communications network. It can be information drawn from other (local) databases, or it can be the result of tool calls that themselves sometimes themselves result in network access. The more power you want from the agent — and for advanced agent RL and evaluation runs, you want a significant amount of power — the more information you’ll need to give it access to. Similarly, evaluations work best when the agent does not know that it’s definitely being evaluated. Sealing your agents behind glass makes this incredibly obvious.