Fix command (#47583)

Author: gewarren

docs/core/tools/dotnet-tool-install.md

@@ -195,7 +195,7 @@ For more information, see [Install a local tool](global-tools.md#install-a-local
 
   Installs [dotnetsay](https://www.nuget.org/packages/dotnetsay/) as a local tool for the current directory.
 
-- **`dotnet tool install -g --verbosity minimal`**
+- **`dotnet tool install -g dotnetsay --verbosity minimal`**
 
   Installs [dotnetsay](https://www.nuget.org/packages/dotnetsay/) as a global tool with the verbosity of minimal. The default verbosity for global tool is quiet.