Is it possible to leave the summary in Portuguese?

In fact you already know that the hints that Visual Studio shows are obtained in the tags tags with% contained in the methods documentation. And you should understand that they are programmers who probably write this. When you write a method and create a summary of the method it probably does it in Portuguese and the VS shows in Portuguese. A programmer in the United States probably writes these tips in English and this is what will be shown to all the programmers in the world.

This does not come from a special file produced by a team that locates products. It is not in resource files, for example. This already gives a hint that although possible it is unlikely that anyone having done all these descriptions in the codes.

Other information such as parameter names will appear. Do you want them translated too? And should the names of the methods be as well? So we came up with the Excel problem in which the functions were translated and there is incompatibility between different language files, which is absurd. Imagine the mess that would make you reading something in Portuguese and programming in English.

Not even the most complete official .NET documentation is translated (unless by machine translation). Microsoft, as well as most of the world, believes that a programmer needs to know at least basic English to be able to program decently and that neither documentation nor even most programming tools need translation. There is a short time that Visual Studio exists in Portuguese and I do not know if the translation is complete, or should it exist.

Even if Microsoft decides to provide descriptions in Portuguese, other vendors will not.

It is possible to get translations, of course, but someone will have to arrange this. That is, unless there is something very well hidden in VS it is not possible to get what you want in a viable way.