diff --git a/rpc/cc/arduino/cli/commands/v1/debug.pb.go b/rpc/cc/arduino/cli/commands/v1/debug.pb.go
index 3103312f81c..d77de884b49 100644
--- a/rpc/cc/arduino/cli/commands/v1/debug.pb.go
+++ b/rpc/cc/arduino/cli/commands/v1/debug.pb.go
@@ -296,7 +296,9 @@ type GetDebugConfigResponse struct {
 	// Extra configuration parameters wrt GDB server
 	ServerConfiguration *anypb.Any `protobuf:"bytes,8,opt,name=server_configuration,json=serverConfiguration,proto3" json:"server_configuration,omitempty"`
 	// Custom debugger configurations (not handled directly by Arduino CLI but
-	// provided for 3rd party plugins/debuggers)
+	// provided for 3rd party plugins/debuggers). The map keys identifies which
+	// 3rd party plugin/debugger is referred, the map string values contains a
+	// JSON configuration for it.
 	CustomConfigs map[string]string `protobuf:"bytes,9,rep,name=custom_configs,json=customConfigs,proto3" json:"custom_configs,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
 	// the SVD file to use
 	SvdFile string `protobuf:"bytes,10,opt,name=svd_file,json=svdFile,proto3" json:"svd_file,omitempty"`
diff --git a/rpc/cc/arduino/cli/commands/v1/debug.proto b/rpc/cc/arduino/cli/commands/v1/debug.proto
index 7d9e9f4c7ac..1b1f8441497 100644
--- a/rpc/cc/arduino/cli/commands/v1/debug.proto
+++ b/rpc/cc/arduino/cli/commands/v1/debug.proto
@@ -92,7 +92,9 @@ message GetDebugConfigResponse {
   // Extra configuration parameters wrt GDB server
   google.protobuf.Any server_configuration = 8;
   // Custom debugger configurations (not handled directly by Arduino CLI but
-  // provided for 3rd party plugins/debuggers)
+  // provided for 3rd party plugins/debuggers). The map keys identifies which
+  // 3rd party plugin/debugger is referred, the map string values contains a
+  // JSON configuration for it.
   map<string, string> custom_configs = 9;
   // the SVD file to use
   string svd_file = 10;