Connecting and disconnecting tool servers changes what the model can do, with no retraining.

The weights are frozen. The world is not.

You cannot retrain a model every time an API appears. So stop trying to put tools inside it. Ask for the tool list at the moment of use, and hand it over as text — the same way you hand over everything else.

Connect or disconnect a server. The conversation is not restarted.

The list can change mid-sentence. A server that gains a tool sends notifications/tools/list_changed, the client re-reads the list, and the next prompt simply contains one more description. New capability, same weights.