diff --git a/docs/reference/schemas/config/functions/contains.md b/docs/reference/schemas/config/functions/contains.md
new file mode 100644
index 000000000..76fc4db1a
--- /dev/null
+++ b/docs/reference/schemas/config/functions/contains.md
@@ -0,0 +1,199 @@
+---
+description: Reference for the 'contains' DSC configuration document function
+ms.date:     08/08/2025
+ms.topic:    reference
+title:       contains
+---
+
+# contains
+
+## Synopsis
+
+Checks whether a collection contains a specific value or whether a string
+contains a substring.
+
+## Syntax
+
+```Syntax
+contains(<collection>, <value>)
+```
+
+## Description
+
+The `contains()` function checks whether a collection (array, object, or
+string) contains a specific value, returning `true` if it does and `false`
+otherwise. For arrays, it checks if the value exists as an element. For
+objects, it checks if the value exists as a property key or value. For
+strings, it checks if the value exists as a substring.
+
+The function accepts string and number values for the search parameter when
+used with arrays, objects, or strings.
+
+## Examples
+
+### Example 1 - Check array for values
+
+The following example shows how to check if an array contains specific values.
+
+```yaml
+# contains.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  myArray:
+    type: array
+    defaultValue:
+    - apple
+    - banana
+    - 42
+    - true
+resources:
+- name: Check array contents
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      hasApple:    "[contains(parameters('myArray'), 'apple')]"
+      hasOrange:   "[contains(parameters('myArray'), 'orange')]"
+      hasNumber42: "[contains(parameters('myArray'), 42)]"
+      hasNumber99: "[contains(parameters('myArray'), 99)]"
+```
+
+```bash
+dsc config get --file contains.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check array contents
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        hasApple: true
+        hasOrange: false
+        hasNumber42: true
+        hasNumber99: false
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Check object for keys and values
+
+The following example shows how to check if an object contains specific keys
+or values.
+
+```yaml
+# contains.example.2.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  myObject:
+    type: object
+    defaultValue:
+      name: John
+      age: 30
+      city: Seattle
+resources:
+- name: Check object contents
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      hasNameKey:      "[contains(parameters('myObject'), 'name')]"
+      hasEmailKey:     "[contains(parameters('myObject'), 'email')]"
+      hasSeattleValue: "[contains(parameters('myObject').city, 'Seattle')]"
+      hasAge30Value:   "[contains(parameters('myObject').age, 30)]"
+```
+
+```bash
+dsc config get --file contains.example.2.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check object contents
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        hasNameKey: true
+        hasEmailKey: false
+        hasSeattleValue: true
+        hasAge30Value: true
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Check string for substrings
+
+The following example shows how to check if a string contains specific
+substrings.
+
+```yaml
+# contains.example.3.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  myString:
+    type: string
+    defaultValue: "Hello DSC 123"
+resources:
+- name: Check string contents
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      hasHello:  "[contains(parameters('myString'), 'Hello')]"
+      hasDSC:  "[contains(parameters('myString'), 'DSC')]"
+      hasNumber: "[contains(parameters('myString'), '123')]"
+      hasXYZ:    "[contains(parameters('myString'), 'XYZ')]"
+```
+
+```bash
+dsc config get --file contains.example.3.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check string contents
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        hasHello: true
+        hasDSC: true
+        hasNumber: true
+        hasXYZ: false
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### collection
+
+The collection to search in (array, object, or string).
+
+```yaml
+Type:         [array, object, string]
+Required:     true
+```
+
+### value
+
+The value to search for. Must be a string or number.
+
+```yaml
+Type:         [string, number]
+Required:     true
+```
+
+The `contains()` function expects exactly two input values. The first
+parameter is the collection to search, and the second is the value to find.
+Complex objects and arrays cannot be used as search values.
+
+## Output
+
+The `contains()` function returns `true` if the collection contains the
+specified value and `false` otherwise.
+
+```yaml
+Type: bool
+```
+
+<!-- Link reference definitions -->
diff --git a/docs/reference/schemas/config/functions/empty.md b/docs/reference/schemas/config/functions/empty.md
new file mode 100644
index 000000000..90fc2a200
--- /dev/null
+++ b/docs/reference/schemas/config/functions/empty.md
@@ -0,0 +1,215 @@
+---
+description: Reference for the 'empty' DSC configuration document function
+ms.date:     08/08/2025
+ms.topic:    reference
+title:       empty
+---
+
+# empty
+
+## Synopsis
+
+Checks whether a value is empty.
+
+## Syntax
+
+```Syntax
+empty(<value>)
+```
+
+## Description
+
+The `empty()` function checks whether a value is empty, returning `true` if
+it is and `false` otherwise. For arrays and objects, it returns `true` if
+they contain no elements or properties. For strings, it returns `true` if
+the string is empty (zero length).
+
+## Examples
+
+### Example 1 - Check empty arrays
+
+The following example shows how to check if arrays are empty.
+
+```yaml
+# empty.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  populatedArray:
+    type: array
+    defaultValue:
+    - item1
+    - item2
+    - item3
+  emptyArray:
+    type: array
+    defaultValue: []
+resources:
+- name: Check array emptiness
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      populatedEmpty: "[empty(parameters('populatedArray'))]"
+      emptyArrayEmpty: "[empty(parameters('emptyArray'))]"
+```
+
+```bash
+dsc config get --file empty.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check array emptiness
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        populatedEmpty: false
+        emptyArrayEmpty: true
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Check empty objects
+
+The following example shows how to check if objects are empty.
+
+```yaml
+# empty.example.2.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  populatedObject:
+    type: object
+    defaultValue:
+      name: John
+      age: 30
+  emptyObject:
+    type: object
+    defaultValue: {}
+resources:
+- name: Check object emptiness
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      populatedEmpty: "[empty(parameters('populatedObject'))]"
+      emptyObjectEmpty: "[empty(parameters('emptyObject'))]"
+```
+
+```bash
+dsc config get --file empty.example.2.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check object emptiness
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        populatedEmpty: false
+        emptyObjectEmpty: true
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Check empty strings
+
+The following example shows how to check if strings are empty.
+
+```yaml
+# empty.example.3.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  populatedString:
+    type: string
+    defaultValue: "Hello World"
+  emptyString:
+    type: string
+    defaultValue: ""
+resources:
+- name: Check string emptiness
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      populatedEmpty: "[empty(parameters('populatedString'))]"
+      emptyStringEmpty: "[empty(parameters('emptyString'))]"
+      literalEmpty: "[empty('')]"
+```
+
+```bash
+dsc config get --file empty.example.3.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check string emptiness
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        populatedEmpty: false
+        emptyStringEmpty: true
+        literalEmpty: true
+messages: []
+hadErrors: false
+```
+
+### Example 4 - Conditional resource deployment
+
+The following example shows a practical use case for checking if a
+configuration array is empty before deploying resources.
+
+```yaml
+# empty.example.4.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  serverList:
+    type: array
+    defaultValue: []
+resources:
+- name: Check if servers configured
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      message: "[if(empty(parameters('serverList')), 'No servers to configure', concat('Configuring ', string(length(parameters('serverList'))), ' servers'))]"
+```
+
+```bash
+dsc config get --file empty.example.4.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check if servers configured
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        message: "No servers to configure"
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### value
+
+The value to check for emptiness.
+
+```yaml
+Type:         [array, object, string]
+Required:     true
+```
+
+The `empty()` function expects exactly one input value of type array, object,
+or string.
+
+## Output
+
+The `empty()` function returns `true` if the value is empty and `false`
+otherwise.
+
+```yaml
+Type: bool
+```
+
+<!-- Link reference definitions -->
diff --git a/docs/reference/schemas/config/functions/length.md b/docs/reference/schemas/config/functions/length.md
new file mode 100644
index 000000000..fee7f77c2
--- /dev/null
+++ b/docs/reference/schemas/config/functions/length.md
@@ -0,0 +1,193 @@
+---
+description: Reference for the 'length' DSC configuration document function
+ms.date:     08/08/2025
+ms.topic:    reference
+title:       length
+---
+
+# length
+
+## Synopsis
+
+Returns the number of elements in an array, properties in an object, or
+characters in a string.
+
+## Syntax
+
+```Syntax
+length(<value>)
+```
+
+## Description
+
+The `length()` function returns the number of elements in a collection or
+characters in a string. For arrays, it returns the count of elements. For
+objects, it returns the count of properties. For strings, it returns the
+count of characters.
+
+## Examples
+
+### Example 1 - Get array length
+
+The following example shows how to get the length of arrays.
+
+```yaml
+# length.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  smallArray:
+    type: array
+    defaultValue:
+    - dsc
+    - v3
+  largeArray:
+    type: array
+    defaultValue:
+    - red
+    - green
+    - blue
+    - yellow
+    - purple
+  emptyArray:
+    type: array
+    defaultValue: []
+resources:
+- name: Check array lengths
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      smallLength: "[length(parameters('smallArray'))]"
+      largeLength: "[length(parameters('largeArray'))]"
+      emptyLength: "[length(parameters('emptyArray'))]"
+```
+
+```bash
+dsc config get --file length.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check array lengths
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        smallLength: 2
+        largeLength: 5
+        emptyLength: 0
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Get object property count
+
+The following example shows how to get the number of properties in objects.
+
+```yaml
+# length.example.2.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  userProfile:
+    type: object
+    defaultValue:
+      firstName: John
+      lastName: Doe
+      email: john.doe@example.com
+      age: 30
+  emptyConfig:
+    type: object
+    defaultValue: {}
+resources:
+- name: Check object property counts
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      profileProperties: "[length(parameters('userProfile'))]"
+      emptyProperties: "[length(parameters('emptyConfig'))]"
+```
+
+```bash
+dsc config get --file length.example.2.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check object property counts
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        profileProperties: 4
+        emptyProperties: 0
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Get string character count
+
+The following example shows how to get the length of strings.
+
+```yaml
+# length.example.3.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  message:
+    type: string
+    defaultValue: "Hello DSC!"
+  longText:
+    type: string
+    defaultValue: "This is a longer string with more characters to demonstrate length calculation."
+resources:
+- name: Check string lengths
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      messageLength: "[length(parameters('message'))]"
+      longTextLength: "[length(parameters('longText'))]"
+      emptyStringLength: "[length('')]"
+      literalLength: "[length('DSC')]"
+```
+
+```bash
+dsc config get --file length.example.3.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Check string lengths
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        messageLength: 10
+        longTextLength: 78
+        emptyStringLength: 0
+        literalLength: 3
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### value
+
+The value to get the length of.
+
+```yaml
+Type:         [array, object, string]
+Required:     true
+```
+
+The `length()` function expects exactly one input value of type array, object,
+or string.
+
+## Output
+
+The `length()` function returns an integer representing the count of elements,
+properties, or characters.
+
+```yaml
+Type: number
+```
+
+<!-- Link reference definitions -->
diff --git a/docs/reference/schemas/config/functions/union.md b/docs/reference/schemas/config/functions/union.md
new file mode 100644
index 000000000..bd13c3269
--- /dev/null
+++ b/docs/reference/schemas/config/functions/union.md
@@ -0,0 +1,314 @@
+---
+description: Reference for the 'union' DSC configuration document function
+ms.date:     08/08/2025
+ms.topic:    reference
+title:       union
+---
+
+# union
+
+## Synopsis
+
+Combines two or more arrays or objects, returning a single collection with
+unique elements or merged properties.
+
+## Syntax
+
+```Syntax
+union(<collection1>, <collection2>, [collection3], ...)
+```
+
+## Description
+
+The `union()` function combines multiple collections into a single collection.
+For arrays, it returns a new array containing all unique elements from the
+input arrays, preserving order and removing duplicates. For objects, it
+merges properties from all input objects, with later objects overriding
+properties from earlier ones when keys conflict.
+
+All input parameters must be of the same type (all arrays or all objects).
+Mixing arrays and objects will result in an error.
+
+## Examples
+
+### Example 1 - Union of arrays
+
+The following example shows how to combine multiple arrays into one.
+
+```yaml
+# union.example.1.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  serverGroup1:
+    type: array
+    defaultValue:
+    - web01
+    - web02
+    - db01
+  serverGroup2:
+    type: array
+    defaultValue:
+    - web02
+    - web03
+    - cache01
+  serverGroup3:
+    type: array
+    defaultValue:
+    - db01
+    - backup01
+resources:
+- name: Combine server groups
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      allServers: "[union(parameters('serverGroup1'), parameters('serverGroup2'))]"
+      threeGroups: "[union(parameters('serverGroup1'), parameters('serverGroup2'), parameters('serverGroup3'))]"
+```
+
+```bash
+dsc config get --file union.example.1.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Combine server groups
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        allServers:
+        - web01
+        - web02
+        - db01
+        - web03
+        - cache01
+        threeGroups:
+        - web01
+        - web02
+        - db01
+        - web03
+        - cache01
+        - backup01
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Union of objects
+
+The following example shows how to merge multiple objects.
+
+```yaml
+# union.example.2.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  defaultConfig:
+    type: object
+    defaultValue:
+      timeout: 30
+      retries: 3
+      debug: false
+  userConfig:
+    type: object
+    defaultValue:
+      timeout: 60
+      logLevel: info
+  envConfig:
+    type: object
+    defaultValue:
+      debug: true
+      environment: production
+resources:
+- name: Merge configurations
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      finalConfig: "[union(parameters('defaultConfig'), parameters('userConfig'), parameters('envConfig'))]"
+```
+
+```bash
+dsc config get --file union.example.2.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Merge configurations
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        finalConfig:
+          timeout: 60
+          retries: 3
+          debug: true
+          logLevel: info
+          environment: production
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Union with duplicate arrays
+
+The following example shows how union handles duplicate values in arrays.
+
+```yaml
+# union.example.3.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  permissions1:
+    type: array
+    defaultValue:
+    - read
+    - write
+    - execute
+  permissions2:
+    type: array
+    defaultValue:
+    - read
+    - admin
+    - delete
+resources:
+- name: Combine permissions
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      uniquePermissions: "[union(parameters('permissions1'), parameters('permissions2'))]"
+      selfUnion: "[union(parameters('permissions1'), parameters('permissions1'))]"
+```
+
+```bash
+dsc config get --file union.example.3.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Combine permissions
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        uniquePermissions:
+        - read
+        - write
+        - execute
+        - admin
+        - delete
+        selfUnion:
+        - read
+        - write
+        - execute
+messages: []
+hadErrors: false
+```
+
+### Example 5 - Union with string conversion for logging
+
+The following example shows how to use union with string conversion for
+building comprehensive log messages.
+
+```yaml
+# union.example.5.dsc.config.yaml
+$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+parameters:
+  baseLogData:
+    type: object
+    defaultValue:
+      timestamp: 1691596800
+      level: "INFO"
+  requestData:
+    type: object
+    defaultValue:
+      requestId: 12345
+      method: "GET"
+  responseData:
+    type: object
+    defaultValue:
+      statusCode: 200
+      duration: 150
+resources:
+- name: Build comprehensive log entry
+  type: Microsoft.DSC.Debug/Echo
+  properties:
+    output:
+      logEntry: "[string(union(parameters('baseLogData'), parameters('requestData'), parameters('responseData')))]"
+      logArray: "[union(createArray('timestamp'), createArray('level', 'requestId'))]"
+```
+
+```bash
+dsc config get --file union.example.5.dsc.config.yaml
+```
+
+```yaml
+results:
+- name: Build comprehensive log entry
+  type: Microsoft.DSC.Debug/Echo
+  result:
+    actualState:
+      output:
+        logEntry: '{"timestamp":1691596800,"level":"INFO","requestId":12345,"method":"GET","statusCode":200,"duration":150}'
+        logArray:
+        - timestamp
+        - level
+        - requestId
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### collection1
+
+The first collection to union.
+
+```yaml
+Type:         [array, object]
+Required:     true
+```
+
+### collection2
+
+The second collection to union. Must be the same type as collection1.
+
+```yaml
+Type:         [array, object]
+Required:     true
+```
+
+### Additional collections
+
+Additional collections to union (optional). All must be the same type as
+collection1.
+
+```yaml
+Type:         [array, object]
+Required:     false
+```
+
+The `union()` function requires at least two input values and accepts
+additional values. All input values must be of the same type (all arrays or
+all objects).
+
+For arrays, the function preserves the order of elements and removes
+duplicates. For objects, properties from later objects override properties
+from earlier objects when there are key conflicts.
+
+## Output
+
+The `union()` function returns a single collection of the same type as the
+input collections.
+
+```yaml
+Type: [array, object]
+```
+
+## Related functions
+
+- [`createArray()`][00] - Creates arrays that can be combined with union
+- [`createObject()`][01] - Creates objects that can be merged with union
+- [`string()`][02] - Converts objects or arrays to JSON strings
+- [`concat()`][03] - Concatenates arrays (alternative to union for arrays)
+
+<!-- Link reference definitions -->
+[00]: ./createArray.md
+[01]: ./createObject.md
+[02]: ./string.md
+[03]: ./concat.md