Update with Copilot remarks

Author: Gijsreyn

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

@@ -1,6 +1,6 @@
 ---
 description: Reference for the 'contains' DSC configuration document function
-ms.date:     08/08/2025
+ms.date:     09/01/2026
 ms.topic:    reference
 title:       contains
 ---
@@ -23,11 +23,14 @@ contains(<collection>, <value>)
 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.
+objects, it checks if the value exists as a property key. The function
+doesn't check object property values. 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.
+used with arrays, objects, or strings. When the search value is a number and
+the collection is an object or a string, DSC compares the number by its
+string representation.
 
 ## Examples
 
@@ -76,10 +79,12 @@ messages: []
 hadErrors: false
 ```
 
-### Example 2 - Check object for keys and values
+### Example 2 - Check object for keys
 
-The following example shows how to check if an object contains specific keys
-or values.
+The following example shows how to check if an object contains specific keys.
+For objects, `contains()` only checks keys, not property values. To check the
+contents of a property value, access the property and check it as a string,
+like the `cityHasSeattle` output in this example.
 
 ```yaml
 # contains.example.2.dsc.config.yaml
@@ -96,10 +101,10 @@ resources:
   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)]"
+      hasNameKey:     "[contains(parameters('myObject'), 'name')]"
+      hasEmailKey:    "[contains(parameters('myObject'), 'email')]"
+      hasAgeKey:      "[contains(parameters('myObject'), 'age')]"
+      cityHasSeattle: "[contains(parameters('myObject').city, 'Seattle')]"
 ```
 
 ```bash
@@ -115,8 +120,8 @@ results:
       output:
         hasNameKey: true
         hasEmailKey: false
-        hasSeattleValue: true
-        hasAge30Value: true
+        hasAgeKey: true
+        cityHasSeattle: true
 messages: []
 hadErrors: false
 ```

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

@@ -20,8 +20,7 @@ dataUri(<stringToConvert>)
 ## Description
 
 The `dataUri()` function converts a string value to a [data URI][01] format. The function encodes
-the input string as base64 and returns it as a data URI with the `application/json` media type and
-`utf8` charset.
+the input string as base64 and returns it as a data URI with the `application/json` media type.
 
 Data URIs are useful for embedding small text content directly in configuration documents,
 especially when the content needs to be passed through systems that expect URI-formatted data.
@@ -179,8 +178,8 @@ MaximumCount: 1
 ## Output
 
 The `dataUri()` function returns a data URI string in the format
-`data:application/json;charset=utf8;base64,<encoded-content>` where `<encoded-content>` is the
-base64 representation of the **stringToConvert** value.
+`data:application/json;base64,<encoded-content>` where `<encoded-content>` is the base64
+representation of the **stringToConvert** value.
 
 ```yaml
 Type: string

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

@@ -84,10 +84,10 @@ hadErrors: false
 
 ## Output
 
-The `systemRoot()` function returns the system root of the current host, or the value overriden
+The `systemRoot()` function returns the system root of the current host, or the value overridden
 using the [`--system-root` command line flag][01].
 
-This is usually `C:\` on Windows system and `/` on Unix systems.
+This is usually `C:\` on Windows systems and `/` on Unix systems.
 
 ```yaml
 Type: string

lib/dsc-lib/src/parser/functions.rs

@@ -43,7 +43,7 @@ pub enum FunctionArg {
 ///
 /// Lambdas are created using the `lambda()` function syntax:
 /// ```text
-/// "[lambda(['item', 'index'], mul(variables('item'), 2))]"
+/// "[lambda('item', 'index', mul(lambdaVariables('item'), 2))]"
 /// ```
 ///
 /// The lambda is stored in the context and referenced by UUID:
@@ -53,7 +53,7 @@ pub enum FunctionArg {
 ///
 /// When used with `map()`, the lambda is invoked for each array element with bound parameters:
 /// ```text
-/// "[map(createArray(1, 2, 3), lambda(['item'], mul(variables('item'), 2)))]"
+/// "[map(createArray(1, 2, 3), lambda('item', mul(lambdaVariables('item'), 2)))]"
 /// ```
 ///
 /// # Lifetime