docs: add stateChanged and restartRequired reference

docs/reference/schemas/config/functions/overview.md

@@ -698,6 +698,10 @@ The following list of functions are for manipulating strings:
 The following list of functions provide system-level information:
 
 - [path()][path] - Construct a file system path from one or more path segments.
+- [restartRequired()][restartRequired] - Return whether a system, service, or process requires a
+  restart.
+- [stateChanged()][stateChanged] - Return whether a resource instance changed state during a
+  `set` operation.
 - [systemRoot()][systemRoot] - Return the system root directory path.
 - [utcNow()][utcNow] - Return the current UTC datetime in a specified format.
 
@@ -767,9 +771,11 @@ The following list of functions create or convert values of a given type:
 [range]:                ./range.md
 [reference]:            ./reference.md
 [resourceId]:           ./resourceId.md
+[restartRequired]:      ./restartRequired.md
 [secret]:               ./secret.md
 [skip]:                 ./skip.md
 [startsWith]:           ./startsWith.md
+[stateChanged]:         ./stateChanged.md
 [string]:               ./string.md
 [take]:                 ./take.md
 [sub]:                  ./sub.md

docs/reference/schemas/config/functions/restartRequired.md

@@ -0,0 +1,117 @@
+---
+description: Reference for the 'restartRequired' DSC configuration document function
+ms.date:     07/11/2026
+ms.topic:    reference
+title:       restartRequired
+---
+
+# restartRequired
+
+## Synopsis
+
+Returns whether a system, service, or process requires a restart.
+
+## Syntax
+
+```Syntax
+restartRequired('<process | service | system>', [name])
+```
+
+## Description
+
+The `restartRequired()` function returns whether a resource in the current configuration operation
+reported a required restart. DSC aggregates restart requirements returned by resources in the
+configuration context.
+
+Use `system` to query whether a system restart is required. Use `service` or `process` to query a
+specific service or process by name. For `service` and `process`, the `name` argument is required.
+For `system`, the `name` argument isn't allowed.
+
+The function returns `false` when no matching restart requirement has been reported.
+
+## Examples
+
+### Example 1 - Query restart requirements
+
+This configuration queries whether installing the OpenSSH Client capability with the
+[Microsoft.Windows/FeatureOnDemandList][01] resource requires a system restart. When the resource
+reports a system restart requirement, `restartRequired()` returns `true`.
+
+> [!NOTE]
+> This example requires Windows, an elevated session, and access to a Windows Update or WSUS
+> source. Capability installation does not always require a restart.
+
+```yaml
+# restartRequired.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Install OpenSSH Client
+  type: Microsoft.Windows/FeatureOnDemandList
+  properties:
+    capabilities:
+    - identity: OpenSSH.Client~~~~0.0.1.0
+      state: Installed
+outputs:
+  systemRestartRequired:
+    type: bool
+    value: "[restartRequired('system')]"
+```
+
+```bash
+dsc config set --file restartRequired.example.1.dsc.config.yaml
+```
+
+When the resource instances report the corresponding restart requirements, DSC returns:
+
+```yaml
+outputs:
+  systemRestartRequired: true
+```
+
+To query a service or process restart requirement, specify its name as the second argument:
+
+```Syntax
+restartRequired('service', 'example-service')
+restartRequired('process', 'example-process')
+```
+
+## Parameters
+
+### kind
+
+The kind of restart requirement to query. The value must be `process`, `service`, or `system`.
+
+```yaml
+Type:         string
+Required:     true
+MinimumCount: 1
+MaximumCount: 1
+AllowedValues:
+- process
+- service
+- system
+```
+
+### name
+
+The name of the process or service to query. This argument is required when **kind** is `process`
+or `service`, and it isn't allowed when **kind** is `system`.
+
+```yaml
+Type:         string
+Required:     conditional
+MinimumCount: 0
+MaximumCount: 1
+```
+
+## Output
+
+The `restartRequired()` function returns `true` when a matching restart requirement was reported
+by a resource in the current configuration operation. Otherwise, it returns `false`.
+
+```yaml
+Type: bool
+```
+
+<!-- Link reference definitions -->
+[01]: ../../../resources/Microsoft/Windows/FeatureOnDemandList/index.md

docs/reference/schemas/config/functions/stateChanged.md

@@ -0,0 +1,107 @@
+---
+description: Reference for the 'stateChanged' DSC configuration document function
+ms.date:     07/11/2026
+ms.topic:    reference
+title:       stateChanged
+---
+
+# stateChanged
+
+## Synopsis
+
+Returns whether a resource instance changed state during the current `set` operation.
+
+## Syntax
+
+```Syntax
+stateChanged(resourceId('<resourceTypeName>', '<instanceName>'))
+```
+
+## Description
+
+The `stateChanged()` function returns `true` when the referenced resource instance changed one or
+more properties during the current `set` operation. Otherwise, it returns `false`.
+
+The function can only evaluate an instance after DSC has executed it. Use [resourceId()][01] to
+identify the instance and add that instance to the calling resource's [dependsOn][02] property.
+When DSC evaluates `stateChanged()` for an instance that has not run or does not exist, it returns
+an error.
+
+## Examples
+
+### Example 1 - Report whether a resource changed state
+
+The configuration sets the **Install OpenSSH Client** instance with the
+[Microsoft.Windows/FeatureOnDemandList][03] resource and then runs the **Report change** instance.
+The second instance uses `stateChanged()` to report whether the feature resource changed state. Its
+`dependsOn` property ensures the feature instance has completed before DSC evaluates the function.
+
+> [!NOTE]
+> This example requires Windows, an elevated session, and access to a Windows Update or WSUS
+> source. The output is `true` only when installing the feature changes state.
+
+```yaml
+# stateChanged.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+resources:
+- name: Install OpenSSH Client
+  type: Microsoft.Windows/FeatureOnDemandList
+  properties:
+    capabilities:
+    - identity: OpenSSH.Client~~~~0.0.1.0
+      state: Installed
+- name: Report change
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output: "[stateChanged(resourceId('Microsoft.Windows/FeatureOnDemandList', 'Install OpenSSH Client'))]"
+  dependsOn:
+  - "[resourceId('Microsoft.Windows/FeatureOnDemandList', 'Install OpenSSH Client')]"
+```
+
+```bash
+dsc config set --file stateChanged.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Install OpenSSH Client
+  type: Microsoft.Windows/FeatureOnDemandList
+  result:
+    changedProperties:
+    - capabilities
+- name: Report change
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    afterState:
+      output: true
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### resourceId
+
+The resource ID of the instance whose state change information you want to retrieve. Use the
+[resourceId()][01] function to create this value.
+
+```yaml
+Type:         string
+Required:     true
+MinimumCount: 1
+MaximumCount: 1
+```
+
+## Output
+
+The `stateChanged()` function returns `true` if the resource changed one or more properties in the
+current `set` operation. Otherwise, it returns `false`.
+
+```yaml
+Type: bool
+```
+
+<!-- Link reference definitions -->
+[01]: ./resourceId.md
+[02]: ../resource.md#dependson
+[03]: ../../../resources/Microsoft/Windows/FeatureOnDemandList/index.md