diff --git a/ntoskrnl/include/internal/kd64.h b/ntoskrnl/include/internal/kd64.h
index d9a68589f44..060832423ba 100644
--- a/ntoskrnl/include/internal/kd64.h
+++ b/ntoskrnl/include/internal/kd64.h
@@ -375,8 +375,7 @@ KdpZeroMemory(
 VOID
 NTAPI
 KdpSysGetVersion(
-    IN PDBGKD_GET_VERSION64 Version
-);
+    _Out_ PDBGKD_GET_VERSION64 Version);
 
 //
 // Context
@@ -401,16 +400,14 @@ KdpSetContextState(
 NTSTATUS
 NTAPI
 KdpSysReadMsr(
-    IN ULONG Msr,
-    OUT PLARGE_INTEGER MsrValue
-);
+    _In_ ULONG Msr,
+    _Out_ PLARGE_INTEGER MsrValue);
 
 NTSTATUS
 NTAPI
 KdpSysWriteMsr(
-    IN ULONG Msr,
-    IN PLARGE_INTEGER MsrValue
-);
+    _In_ ULONG Msr,
+    _In_ PLARGE_INTEGER MsrValue);
 
 //
 // Bus
@@ -418,26 +415,24 @@ KdpSysWriteMsr(
 NTSTATUS
 NTAPI
 KdpSysReadBusData(
-    IN ULONG BusDataType,
-    IN ULONG BusNumber,
-    IN ULONG SlotNumber,
-    IN ULONG Offset,
-    IN PVOID Buffer,
-    IN ULONG Length,
-    OUT PULONG ActualLength
-);
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength);
 
 NTSTATUS
 NTAPI
 KdpSysWriteBusData(
-    IN ULONG BusDataType,
-    IN ULONG BusNumber,
-    IN ULONG SlotNumber,
-    IN ULONG Offset,
-    IN PVOID Buffer,
-    IN ULONG Length,
-    OUT PULONG ActualLength
-);
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength);
 
 //
 // Control Space
@@ -445,22 +440,20 @@ KdpSysWriteBusData(
 NTSTATUS
 NTAPI
 KdpSysReadControlSpace(
-    IN ULONG Processor,
-    IN ULONG64 BaseAddress,
-    IN PVOID Buffer,
-    IN ULONG Length,
-    OUT PULONG ActualLength
-);
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength);
 
 NTSTATUS
 NTAPI
 KdpSysWriteControlSpace(
-    IN ULONG Processor,
-    IN ULONG64 BaseAddress,
-    IN PVOID Buffer,
-    IN ULONG Length,
-    OUT PULONG ActualLength
-);
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength);
 
 //
 // I/O Space
@@ -468,26 +461,24 @@ KdpSysWriteControlSpace(
 NTSTATUS
 NTAPI
 KdpSysReadIoSpace(
-    IN ULONG InterfaceType,
-    IN ULONG BusNumber,
-    IN ULONG AddressSpace,
-    IN ULONG64 IoAddress,
-    IN PVOID DataValue,
-    IN ULONG DataSize,
-    OUT PULONG ActualDataSize
-);
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _Out_writes_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize);
 
 NTSTATUS
 NTAPI
 KdpSysWriteIoSpace(
-    IN ULONG InterfaceType,
-    IN ULONG BusNumber,
-    IN ULONG AddressSpace,
-    IN ULONG64 IoAddress,
-    IN PVOID DataValue,
-    IN ULONG DataSize,
-    OUT PULONG ActualDataSize
-);
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _In_reads_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize);
 
 //
 // Low Memory
diff --git a/ntoskrnl/kd64/amd64/kdx64.c b/ntoskrnl/kd64/amd64/kdx64.c
index 5c6871d3a9e..b403bfa5918 100644
--- a/ntoskrnl/kd64/amd64/kdx64.c
+++ b/ntoskrnl/kd64/amd64/kdx64.c
@@ -93,8 +93,9 @@ KdpSetContextState(IN PDBGKD_ANY_WAIT_STATE_CHANGE WaitStateChange,
 
 NTSTATUS
 NTAPI
-KdpSysReadMsr(IN ULONG Msr,
-              OUT PLARGE_INTEGER MsrValue)
+KdpSysReadMsr(
+    _In_ ULONG Msr,
+    _Out_ PLARGE_INTEGER MsrValue)
 {
     /* Use SEH to protect from invalid MSRs */
     _SEH2_TRY
@@ -112,8 +113,9 @@ KdpSysReadMsr(IN ULONG Msr,
 
 NTSTATUS
 NTAPI
-KdpSysWriteMsr(IN ULONG Msr,
-               IN PLARGE_INTEGER MsrValue)
+KdpSysWriteMsr(
+    _In_ ULONG Msr,
+    _In_ PLARGE_INTEGER MsrValue)
 {
     /* Use SEH to protect from invalid MSRs */
     _SEH2_TRY
@@ -131,13 +133,14 @@ KdpSysWriteMsr(IN ULONG Msr,
 
 NTSTATUS
 NTAPI
-KdpSysReadBusData(IN ULONG BusDataType,
-                  IN ULONG BusNumber,
-                  IN ULONG SlotNumber,
-                  IN ULONG Offset,
-                  IN PVOID Buffer,
-                  IN ULONG Length,
-                  OUT PULONG ActualLength)
+KdpSysReadBusData(
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -145,13 +148,14 @@ KdpSysReadBusData(IN ULONG BusDataType,
 
 NTSTATUS
 NTAPI
-KdpSysWriteBusData(IN ULONG BusDataType,
-                   IN ULONG BusNumber,
-                   IN ULONG SlotNumber,
-                   IN ULONG Offset,
-                   IN PVOID Buffer,
-                   IN ULONG Length,
-                   OUT PULONG ActualLength)
+KdpSysWriteBusData(
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -159,11 +163,12 @@ KdpSysWriteBusData(IN ULONG BusDataType,
 
 NTSTATUS
 NTAPI
-KdpSysReadControlSpace(IN ULONG Processor,
-                       IN ULONG64 BaseAddress,
-                       IN PVOID Buffer,
-                       IN ULONG Length,
-                       OUT PULONG ActualLength)
+KdpSysReadControlSpace(
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     PVOID ControlStart;
     PKPRCB Prcb = KiProcessorBlock[Processor];
@@ -210,11 +215,12 @@ KdpSysReadControlSpace(IN ULONG Processor,
 
 NTSTATUS
 NTAPI
-KdpSysWriteControlSpace(IN ULONG Processor,
-                        IN ULONG64 BaseAddress,
-                        IN PVOID Buffer,
-                        IN ULONG Length,
-                        OUT PULONG ActualLength)
+KdpSysWriteControlSpace(
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     PVOID ControlStart;
     PKPRCB Prcb = KiProcessorBlock[Processor];
@@ -241,13 +247,14 @@ KdpSysWriteControlSpace(IN ULONG Processor,
 
 NTSTATUS
 NTAPI
-KdpSysReadIoSpace(IN ULONG InterfaceType,
-                  IN ULONG BusNumber,
-                  IN ULONG AddressSpace,
-                  IN ULONG64 IoAddress,
-                  OUT PVOID DataValue,
-                  IN ULONG DataSize,
-                  OUT PULONG ActualDataSize)
+KdpSysReadIoSpace(
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _Out_writes_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize)
 {
     /* Verify parameters */
     if (InterfaceType != Isa || BusNumber != 0 || AddressSpace != 1)
@@ -297,13 +304,14 @@ KdpSysReadIoSpace(IN ULONG InterfaceType,
 
 NTSTATUS
 NTAPI
-KdpSysWriteIoSpace(IN ULONG InterfaceType,
-                   IN ULONG BusNumber,
-                   IN ULONG AddressSpace,
-                   IN ULONG64 IoAddress,
-                   IN PVOID DataValue,
-                   IN ULONG DataSize,
-                   OUT PULONG ActualDataSize)
+KdpSysWriteIoSpace(
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _In_reads_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize)
 {
     /* Verify parameters */
     if (InterfaceType != Isa || BusNumber != 0 || AddressSpace != 1)
diff --git a/ntoskrnl/kd64/arm/kdarm.c b/ntoskrnl/kd64/arm/kdarm.c
index a62956d1065..e322726c548 100644
--- a/ntoskrnl/kd64/arm/kdarm.c
+++ b/ntoskrnl/kd64/arm/kdarm.c
@@ -35,8 +35,9 @@ KdpSetContextState(IN PDBGKD_ANY_WAIT_STATE_CHANGE WaitStateChange,
 
 NTSTATUS
 NTAPI
-KdpSysReadMsr(IN ULONG Msr,
-              OUT PLARGE_INTEGER MsrValue)
+KdpSysReadMsr(
+    _In_ ULONG Msr,
+    _Out_ PLARGE_INTEGER MsrValue)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -44,8 +45,9 @@ KdpSysReadMsr(IN ULONG Msr,
 
 NTSTATUS
 NTAPI
-KdpSysWriteMsr(IN ULONG Msr,
-               IN PLARGE_INTEGER MsrValue)
+KdpSysWriteMsr(
+    _In_ ULONG Msr,
+    _In_ PLARGE_INTEGER MsrValue)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -53,13 +55,14 @@ KdpSysWriteMsr(IN ULONG Msr,
 
 NTSTATUS
 NTAPI
-KdpSysReadBusData(IN ULONG BusDataType,
-                  IN ULONG BusNumber,
-                  IN ULONG SlotNumber,
-                  IN ULONG Offset,
-                  IN PVOID Buffer,
-                  IN ULONG Length,
-                  OUT PULONG ActualLength)
+KdpSysReadBusData(
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -67,13 +70,14 @@ KdpSysReadBusData(IN ULONG BusDataType,
 
 NTSTATUS
 NTAPI
-KdpSysWriteBusData(IN ULONG BusDataType,
-                   IN ULONG BusNumber,
-                   IN ULONG SlotNumber,
-                   IN ULONG Offset,
-                   IN PVOID Buffer,
-                   IN ULONG Length,
-                   OUT PULONG ActualLength)
+KdpSysWriteBusData(
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -81,11 +85,12 @@ KdpSysWriteBusData(IN ULONG BusDataType,
 
 NTSTATUS
 NTAPI
-KdpSysReadControlSpace(IN ULONG Processor,
-                       IN ULONG64 BaseAddress,
-                       IN PVOID Buffer,
-                       IN ULONG Length,
-                       OUT PULONG ActualLength)
+KdpSysReadControlSpace(
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -93,11 +98,12 @@ KdpSysReadControlSpace(IN ULONG Processor,
 
 NTSTATUS
 NTAPI
-KdpSysWriteControlSpace(IN ULONG Processor,
-                        IN ULONG64 BaseAddress,
-                        IN PVOID Buffer,
-                        IN ULONG Length,
-                        OUT PULONG ActualLength)
+KdpSysWriteControlSpace(
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -105,13 +111,14 @@ KdpSysWriteControlSpace(IN ULONG Processor,
 
 NTSTATUS
 NTAPI
-KdpSysReadIoSpace(IN ULONG InterfaceType,
-                  IN ULONG BusNumber,
-                  IN ULONG AddressSpace,
-                  IN ULONG64 IoAddress,
-                  IN PVOID DataValue,
-                  IN ULONG DataSize,
-                  OUT PULONG ActualDataSize)
+KdpSysReadIoSpace(
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _Out_writes_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
@@ -119,13 +126,14 @@ KdpSysReadIoSpace(IN ULONG InterfaceType,
 
 NTSTATUS
 NTAPI
-KdpSysWriteIoSpace(IN ULONG InterfaceType,
-                   IN ULONG BusNumber,
-                   IN ULONG AddressSpace,
-                   IN ULONG64 IoAddress,
-                   IN PVOID DataValue,
-                   IN ULONG DataSize,
-                   OUT PULONG ActualDataSize)
+KdpSysWriteIoSpace(
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _In_reads_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize)
 {
     UNIMPLEMENTED;
     return STATUS_UNSUCCESSFUL;
diff --git a/ntoskrnl/kd64/i386/kdx86.c b/ntoskrnl/kd64/i386/kdx86.c
index 843f6e88b0d..64736cc8ef6 100644
--- a/ntoskrnl/kd64/i386/kdx86.c
+++ b/ntoskrnl/kd64/i386/kdx86.c
@@ -91,8 +91,9 @@ KdpSetContextState(IN PDBGKD_ANY_WAIT_STATE_CHANGE WaitStateChange,
 
 NTSTATUS
 NTAPI
-KdpSysReadMsr(IN ULONG Msr,
-              OUT PLARGE_INTEGER MsrValue)
+KdpSysReadMsr(
+    _In_ ULONG Msr,
+    _Out_ PLARGE_INTEGER MsrValue)
 {
     /* Wrap this in SEH in case the MSR doesn't exist */
     _SEH2_TRY
@@ -113,8 +114,9 @@ KdpSysReadMsr(IN ULONG Msr,
 
 NTSTATUS
 NTAPI
-KdpSysWriteMsr(IN ULONG Msr,
-               IN PLARGE_INTEGER MsrValue)
+KdpSysWriteMsr(
+    _In_ ULONG Msr,
+    _In_ PLARGE_INTEGER MsrValue)
 {
     /* Wrap this in SEH in case the MSR doesn't exist */
     _SEH2_TRY
@@ -135,13 +137,14 @@ KdpSysWriteMsr(IN ULONG Msr,
 
 NTSTATUS
 NTAPI
-KdpSysReadBusData(IN ULONG BusDataType,
-                  IN ULONG BusNumber,
-                  IN ULONG SlotNumber,
-                  IN ULONG Offset,
-                  IN PVOID Buffer,
-                  IN ULONG Length,
-                  OUT PULONG ActualLength)
+KdpSysReadBusData(
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     /* Just forward to HAL */
     *ActualLength = HalGetBusDataByOffset(BusDataType,
@@ -157,13 +160,14 @@ KdpSysReadBusData(IN ULONG BusDataType,
 
 NTSTATUS
 NTAPI
-KdpSysWriteBusData(IN ULONG BusDataType,
-                   IN ULONG BusNumber,
-                   IN ULONG SlotNumber,
-                   IN ULONG Offset,
-                   IN PVOID Buffer,
-                   IN ULONG Length,
-                   OUT PULONG ActualLength)
+KdpSysWriteBusData(
+    _In_ BUS_DATA_TYPE BusDataType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG SlotNumber,
+    _In_ ULONG Offset,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     /* Just forward to HAL */
     *ActualLength = HalSetBusDataByOffset(BusDataType,
@@ -179,11 +183,12 @@ KdpSysWriteBusData(IN ULONG BusDataType,
 
 NTSTATUS
 NTAPI
-KdpSysReadControlSpace(IN ULONG Processor,
-                       IN ULONG64 BaseAddress,
-                       IN PVOID Buffer,
-                       IN ULONG Length,
-                       OUT PULONG ActualLength)
+KdpSysReadControlSpace(
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _Out_writes_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     PVOID ControlStart;
     ULONG RealLength;
@@ -219,11 +224,12 @@ KdpSysReadControlSpace(IN ULONG Processor,
 
 NTSTATUS
 NTAPI
-KdpSysWriteControlSpace(IN ULONG Processor,
-                        IN ULONG64 BaseAddress,
-                        IN PVOID Buffer,
-                        IN ULONG Length,
-                        OUT PULONG ActualLength)
+KdpSysWriteControlSpace(
+    _In_ ULONG Processor,
+    _In_ ULONG64 BaseAddress,
+    _In_reads_bytes_(Length) PVOID Buffer,
+    _In_ ULONG Length,
+    _Out_ PULONG ActualLength)
 {
     PVOID ControlStart;
 
@@ -254,13 +260,14 @@ KdpSysWriteControlSpace(IN ULONG Processor,
 
 NTSTATUS
 NTAPI
-KdpSysReadIoSpace(IN ULONG InterfaceType,
-                  IN ULONG BusNumber,
-                  IN ULONG AddressSpace,
-                  IN ULONG64 IoAddress,
-                  IN PVOID DataValue,
-                  IN ULONG DataSize,
-                  OUT PULONG ActualDataSize)
+KdpSysReadIoSpace(
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _Out_writes_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize)
 {
     NTSTATUS Status;
 
@@ -335,13 +342,14 @@ KdpSysReadIoSpace(IN ULONG InterfaceType,
 
 NTSTATUS
 NTAPI
-KdpSysWriteIoSpace(IN ULONG InterfaceType,
-                   IN ULONG BusNumber,
-                   IN ULONG AddressSpace,
-                   IN ULONG64 IoAddress,
-                   IN PVOID DataValue,
-                   IN ULONG DataSize,
-                   OUT PULONG ActualDataSize)
+KdpSysWriteIoSpace(
+    _In_ INTERFACE_TYPE InterfaceType,
+    _In_ ULONG BusNumber,
+    _In_ ULONG AddressSpace,
+    _In_ ULONG64 IoAddress,
+    _In_reads_bytes_(DataSize) PVOID DataValue,
+    _In_ ULONG DataSize,
+    _Out_ PULONG ActualDataSize)
 {
     NTSTATUS Status;
 
diff --git a/ntoskrnl/kd64/kdapi.c b/ntoskrnl/kd64/kdapi.c
index 4baeb4d9c42..bd27655346b 100644
--- a/ntoskrnl/kd64/kdapi.c
+++ b/ntoskrnl/kd64/kdapi.c
@@ -430,7 +430,8 @@ KdpSetCommonState(IN ULONG NewState,
 
 VOID
 NTAPI
-KdpSysGetVersion(IN PDBGKD_GET_VERSION64 Version)
+KdpSysGetVersion(
+    _Out_ PDBGKD_GET_VERSION64 Version)
 {
     /* Copy the version block */
     KdpMoveMemory(Version,