diff --git a/packages/firestore/src/lite-api/expressions.ts b/packages/firestore/src/lite-api/expressions.ts
index 03182ae3227..bd35bc4ae97 100644
--- a/packages/firestore/src/lite-api/expressions.ts
+++ b/packages/firestore/src/lite-api/expressions.ts
@@ -698,7 +698,8 @@ export abstract class Expr implements ProtoValueSerializable, UserData {
   }
 
   /**
-   * Creates an expression that checks if a field exists in the document.
+   * Creates an expression that checks if this expression evaluates to a name of
+   * the field that exists.
    *
    * ```typescript
    * // Check if the document has a field named "phoneNumber"
@@ -1889,7 +1890,7 @@ export abstract class Expr implements ProtoValueSerializable, UserData {
    * ```
    *
    * @param key The name of the key to remove from the input map.
-   * @returns A new {@code FirestoreFunction} representing the 'mapRemove' operation.
+   * @return A new {@code Expr} that evaluates to a modified map.
    */
   mapRemove(key: string): FunctionExpr;
   /**
@@ -1903,7 +1904,7 @@ export abstract class Expr implements ProtoValueSerializable, UserData {
    * ```
    *
    * @param keyExpr An expression that produces the name of the key to remove from the input map.
-   * @returns A new {@code FirestoreFunction} representing the 'mapRemove' operation.
+   * @return A new {@code Expr} that evaluates to a modified map.
    */
   mapRemove(keyExpr: Expr): FunctionExpr;
   mapRemove(stringExpr: Expr | string): FunctionExpr {
@@ -1916,7 +1917,8 @@ export abstract class Expr implements ProtoValueSerializable, UserData {
   /**
    * @beta
    *
-   * Creates an expression that merges multiple map values.
+   * Creates an expression that merges multiple maps into a single map. If
+   * multiple maps have the same key, the later value is used.
    *
    * ```
    * // Merges the map in the settings field with, a map literal, and a map in
@@ -1928,8 +1930,7 @@ export abstract class Expr implements ProtoValueSerializable, UserData {
    * an expression that returns a map.
    * @param otherMaps Optional additional maps to merge. Each map is represented
    * as a literal or an expression that returns a map.
-   *
-   * @returns A new {@code FirestoreFunction} representing the 'mapMerge' operation.
+   * @return A new {@code Expr} that evaluates to a merged map.
    */
   mapMerge(
     secondMap: Record<string, unknown> | Expr,
@@ -2556,17 +2557,17 @@ export class BooleanExpr extends FunctionExpr {
  * countIf(field("is_active").eq(true)).as("numActiveDocuments");
  * ```
  *
- * @param booleanExpr - The boolean expression to evaluate on each input.
+ * @param condition The boolean expression to evaluate on each input.
  * @returns A new `AggregateFunction` representing the 'countIf' aggregation.
  */
-export function countIf(booleanExpr: BooleanExpr): AggregateFunction {
-  return booleanExpr.countIf();
+export function countIf(condition: BooleanExpr): AggregateFunction {
+  return condition.countIf();
 }
 
 /**
  * @beta
- * Creates an expression that return a pseudo-random value of type double in the
- * range of [0, 1), inclusive of 0 and exclusive of 1.
+ * Creates an expression that return a pseudo-random number of type double in
+ * the range of [0, 1), inclusive of 0 and exclusive of 1.
  *
  * @returns A new `Expr` representing the 'rand' function.
  */
@@ -3139,7 +3140,7 @@ export function isAbsent(value: Expr | string): BooleanExpr {
 /**
  * @beta
  *
- * Creates an expression that checks if an expression evaluates to 'NaN' (Not a Number).
+ * Creates an expression that checks if tbe result of an expression is null.
  *
  * ```typescript
  * // Check if the result of a calculation is NaN
@@ -3147,14 +3148,14 @@ export function isAbsent(value: Expr | string): BooleanExpr {
  * ```
  *
  * @param value The expression to check.
- * @return A new {@code Expr} representing the 'isNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNull' check.
  */
 export function isNull(value: Expr): BooleanExpr;
 
 /**
  * @beta
  *
- * Creates an expression that checks if a field's value evaluates to 'NaN' (Not a Number).
+ * Creates an expression that checks if tbe value of a field is null.
  *
  * ```typescript
  * // Check if the result of a calculation is NaN
@@ -3162,7 +3163,7 @@ export function isNull(value: Expr): BooleanExpr;
  * ```
  *
  * @param value The name of the field to check.
- * @return A new {@code Expr} representing the 'isNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNull' check.
  */
 export function isNull(value: string): BooleanExpr;
 export function isNull(value: Expr | string): BooleanExpr {
@@ -3180,7 +3181,7 @@ export function isNull(value: Expr | string): BooleanExpr {
  * ```
  *
  * @param value The expression to check.
- * @return A new {@code Expr} representing the 'isNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNotNull' check.
  */
 export function isNotNull(value: Expr): BooleanExpr;
 
@@ -3195,7 +3196,7 @@ export function isNotNull(value: Expr): BooleanExpr;
  * ```
  *
  * @param value The name of the field to check.
- * @return A new {@code Expr} representing the 'isNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNotNull' check.
  */
 export function isNotNull(value: string): BooleanExpr;
 export function isNotNull(value: Expr | string): BooleanExpr {
@@ -3213,7 +3214,7 @@ export function isNotNull(value: Expr | string): BooleanExpr {
  * ```
  *
  * @param value The expression to check.
- * @return A new {@code Expr} representing the 'isNotNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNotNaN' check.
  */
 export function isNotNan(value: Expr): BooleanExpr;
 
@@ -3228,7 +3229,7 @@ export function isNotNan(value: Expr): BooleanExpr;
  * ```
  *
  * @param value The name of the field to check.
- * @return A new {@code Expr} representing the 'isNotNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNotNaN' check.
  */
 export function isNotNan(value: string): BooleanExpr;
 export function isNotNan(value: Expr | string): BooleanExpr {
@@ -3247,6 +3248,7 @@ export function isNotNan(value: Expr | string): BooleanExpr {
  *
  * @param mapField The name of a field containing a map value.
  * @param key The name of the key to remove from the input map.
+ * @return A new {@code Expr} that evaluates to a modified map.
  */
 export function mapRemove(mapField: string, key: string): FunctionExpr;
 /**
@@ -3261,6 +3263,7 @@ export function mapRemove(mapField: string, key: string): FunctionExpr;
  *
  * @param mapExpr An expression return a map value.
  * @param key The name of the key to remove from the input map.
+ * @return A new {@code Expr} that evaluates to a modified map.
  */
 export function mapRemove(mapExpr: Expr, key: string): FunctionExpr;
 /**
@@ -3275,6 +3278,7 @@ export function mapRemove(mapExpr: Expr, key: string): FunctionExpr;
  *
  * @param mapField The name of a field containing a map value.
  * @param keyExpr An expression that produces the name of the key to remove from the input map.
+ * @return A new {@code Expr} that evaluates to a modified map.
  */
 export function mapRemove(mapField: string, keyExpr: Expr): FunctionExpr;
 /**
@@ -3289,6 +3293,7 @@ export function mapRemove(mapField: string, keyExpr: Expr): FunctionExpr;
  *
  * @param mapExpr An expression return a map value.
  * @param keyExpr An expression that produces the name of the key to remove from the input map.
+ * @return A new {@code Expr} that evaluates to a modified map.
  */
 export function mapRemove(mapExpr: Expr, keyExpr: Expr): FunctionExpr;
 
@@ -3302,7 +3307,8 @@ export function mapRemove(
 /**
  * @beta
  *
- * Creates an expression that merges multiple map values.
+ * Creates an expression that merges multiple maps into a single map. If
+ * multiple maps have the same key, the later value is used.
  *
  * ```
  * // Merges the map in the settings field with, a map literal, and a map in
@@ -3315,6 +3321,7 @@ export function mapRemove(
  * an expression that returns a map.
  * @param otherMaps Optional additional maps to merge. Each map is represented
  * as a literal or an expression that returns a map.
+ * @return A new {@code Expr} that evaluates to a merged map.
  */
 export function mapMerge(
   mapField: string,
@@ -3325,7 +3332,8 @@ export function mapMerge(
 /**
  * @beta
  *
- * Creates an expression that merges multiple map values.
+ * Creates an expression that merges multiple maps into a single map. If
+ * multiple maps have the same key, the later value is used.
  *
  * ```
  * // Merges the map in the settings field with, a map literal, and a map in
@@ -3338,6 +3346,7 @@ export function mapMerge(
  * an expression that returns a map.
  * @param otherMaps Optional additional maps to merge. Each map is represented
  * as a literal or an expression that returns a map.
+ * @return A new {@code Expr} that evaluates to a merged map.
  */
 export function mapMerge(
   firstMap: Record<string, unknown> | Expr,
@@ -3777,6 +3786,7 @@ export function mod(fieldName: string, expression: Expr): FunctionExpr;
  * @param value The divisor constant.
  * @return A new {@code Expr} representing the modulo operation.
  */
+// TODO: Should we only accept number constants on arithmetic operations? (including others)
 export function mod(fieldName: string, value: unknown): FunctionExpr;
 export function mod(left: Expr | string, right: Expr | unknown): FunctionExpr {
   const normalizedLeft = typeof left === 'string' ? field(left) : left;
@@ -4664,7 +4674,7 @@ export function eqAny(
  *
  * @param fieldName The field to compare.
  * @param arrayExpression An expression that evaluates to an array, whose elements to check for equality to the input field.
- * @return A new {@code Expr} representing the 'IN' comparison.
+ * @return A new {@code BooleanExpr} representing the 'IN' comparison.
  */
 export function eqAny(fieldName: string, arrayExpression: Expr): BooleanExpr;
 export function eqAny(
@@ -4678,7 +4688,7 @@ export function eqAny(
 /**
  * @beta
  *
- * Creates an expression that checks if an expression is not equal to any of the provided values
+ * Creates an expression that checks if an expression is not equal to all the provided values
  * or expressions.
  *
  * ```typescript
@@ -4688,7 +4698,7 @@ export function eqAny(
  *
  * @param element The expression to compare.
  * @param values The values to check against.
- * @return A new {@code Expr} representing the 'NOT IN' comparison.
+ * @return A new {@code BooleanExpr} representing the 'NOT IN' comparison.
  */
 export function notEqAny(
   element: Expr,
@@ -4698,7 +4708,7 @@ export function notEqAny(
 /**
  * @beta
  *
- * Creates an expression that checks if a field's value is not equal to any of the provided values
+ * Creates an expression that checks if a field's value is not equal to all the provided values
  * or expressions.
  *
  * ```typescript
@@ -4708,7 +4718,7 @@ export function notEqAny(
  *
  * @param fieldName The field name to compare.
  * @param values The values to check against.
- * @return A new {@code Expr} representing the 'NOT IN' comparison.
+ * @return A new {@code BooleanExpr} representing the 'NOT IN' comparison.
  */
 export function notEqAny(
   fieldName: string,
@@ -4718,7 +4728,7 @@ export function notEqAny(
 /**
  * @beta
  *
- * Creates an expression that checks if an expression is not equal to any of the provided values
+ * Creates an expression that checks if an expression is not equal to all the provided values
  * or expressions.
  *
  * ```typescript
@@ -4728,14 +4738,14 @@ export function notEqAny(
  *
  * @param element The expression to compare.
  * @param arrayExpression The values to check against.
- * @return A new {@code Expr} representing the 'NOT IN' comparison.
+ * @return A new {@code BooleanExpr} representing the 'NOT IN' comparison.
  */
 export function notEqAny(element: Expr, arrayExpression: Expr): BooleanExpr;
 
 /**
  * @beta
  *
- * Creates an expression that checks if a field's value is not equal to any of the values in the evaluated expression.
+ * Creates an expression that checks if a field's value is not equal to all the values in the evaluated expression.
  *
  * ```typescript
  * // Check if the 'status' field is not equal to any value in the field 'rejectedStatuses'
@@ -4744,7 +4754,7 @@ export function notEqAny(element: Expr, arrayExpression: Expr): BooleanExpr;
  *
  * @param fieldName The field name to compare.
  * @param arrayExpression The values to check against.
- * @return A new {@code Expr} representing the 'NOT IN' comparison.
+ * @return A new {@code BooleanExpr} representing the 'NOT IN' comparison.
  */
 export function notEqAny(fieldName: string, arrayExpression: Expr): BooleanExpr;
 
@@ -4773,7 +4783,7 @@ export function notEqAny(
  * @param first The first condition.
  * @param second The second condition.
  * @param additionalConditions Additional conditions to 'XOR' together.
- * @return A new {@code Expr} representing the logical 'XOR' operation.
+ * @return A new {@code BooleanExpr} representing the logical 'XOR' operation.
  */
 export function xor(
   first: BooleanExpr,
@@ -4951,7 +4961,7 @@ export function logicalMinimum(
  * ```
  *
  * @param value An expression evaluates to the name of the field to check.
- * @return A new {@code Expr} representing the 'exists' check.
+ * @return A new {@code BooleanExpr} representing the 'exists' check.
  */
 export function exists(value: Expr): BooleanExpr;
 
@@ -4966,7 +4976,7 @@ export function exists(value: Expr): BooleanExpr;
  * ```
  *
  * @param fieldName The field name to check.
- * @return A new {@code Expr} representing the 'exists' check.
+ * @return A new {@code BooleanExpr} representing the 'exists' check.
  */
 export function exists(fieldName: string): BooleanExpr;
 export function exists(valueOrField: Expr | string): BooleanExpr {
@@ -4984,7 +4994,7 @@ export function exists(valueOrField: Expr | string): BooleanExpr {
  * ```
  *
  * @param value The expression to check.
- * @return A new {@code Expr} representing the 'isNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNaN' check.
  */
 export function isNan(value: Expr): BooleanExpr;
 
@@ -4999,7 +5009,7 @@ export function isNan(value: Expr): BooleanExpr;
  * ```
  *
  * @param fieldName The name of the field to check.
- * @return A new {@code Expr} representing the 'isNaN' check.
+ * @return A new {@code BooleanExpr} representing the 'isNaN' check.
  */
 export function isNan(fieldName: string): BooleanExpr;
 export function isNan(value: Expr | string): BooleanExpr {
@@ -5017,21 +5027,21 @@ export function isNan(value: Expr | string): BooleanExpr {
  * ```
  *
  * @param stringExpression An expression evaluating to a string value, which will be reversed.
- * @return A new {@code Expr} representing the reversed string.
+ * @return A new {@code BooleanExpr} representing the reversed string.
  */
 export function reverse(stringExpression: Expr): FunctionExpr;
 
 /**
  * @beta
  *
- * Creates an expression that reverses a string value in the specified field.
+ * Creates an expression that reverses a string value from the specified field.
  *
  * ```typescript
  * // Reverse the value of the 'myString' field.
  * reverse("myString");
  * ```
  *
- * @param field The name of the field representing the string to reverse.
+ * @param field The name of the field that contains the string to reverse.
  * @return A new {@code Expr} representing the reversed string.
  */
 export function reverse(field: string): FunctionExpr;
@@ -5049,13 +5059,13 @@ export function reverse(expr: Expr | string): FunctionExpr {
  * replaceFirst(field("message"), "hello", "hi");
  * ```
  *
- * @param value The expression representing the string to perform the replacement on.
+ * @param stringExpression The expression representing the string to perform the replacement on.
  * @param find The substring to search for.
- * @param replace The substring to replace the first occurrence of 'find' with.
+ * @param replace The replacement for the first occurrence of 'find'.
  * @return A new {@code Expr} representing the string with the first occurrence replaced.
  */
 export function replaceFirst(
-  value: Expr,
+  stringExpression: Expr,
   find: string,
   replace: string
 ): FunctionExpr;
@@ -5071,13 +5081,13 @@ export function replaceFirst(
  * replaceFirst(field("message"), field("findField"), field("replaceField"));
  * ```
  *
- * @param value The expression representing the string to perform the replacement on.
+ * @param stringExpression The expression representing the string to perform the replacement on.
  * @param find The expression representing the substring to search for.
- * @param replace The expression representing the substring to replace the first occurrence of 'find' with.
+ * @param replace The expression representing the replacement for first occurrence of 'find'.
  * @return A new {@code Expr} representing the string with the first occurrence replaced.
  */
 export function replaceFirst(
-  value: Expr,
+  stringExpression: Expr,
   find: Expr,
   replace: Expr
 ): FunctionExpr;
@@ -5085,7 +5095,7 @@ export function replaceFirst(
 /**
  * @beta
  *
- * Creates an expression that replaces the first occurrence of a substring within a string represented by a field with another substring.
+ * Creates an expression that replaces the first occurrence of a substring within the specified string field.
  *
  * ```typescript
  * // Replace the first occurrence of "hello" with "hi" in the 'message' field.
@@ -5094,7 +5104,7 @@ export function replaceFirst(
  *
  * @param fieldName The name of the field representing the string to perform the replacement on.
  * @param find The substring to search for.
- * @param replace The substring to replace the first occurrence of 'find' with.
+ * @param replace The replacement for the first occurrence of 'find'.
  * @return A new {@code Expr} representing the string with the first occurrence replaced.
  */
 export function replaceFirst(
@@ -5123,13 +5133,13 @@ export function replaceFirst(
  * replaceAll(field("message"), "hello", "hi");
  * ```
  *
- * @param value The expression representing the string to perform the replacement on.
+ * @param stringExpression The expression representing the string to perform the replacement on.
  * @param find The substring to search for.
  * @param replace The substring to replace all occurrences of 'find' with.
  * @return A new {@code Expr} representing the string with all occurrences replaced.
  */
 export function replaceAll(
-  value: Expr,
+  stringExpression: Expr,
   find: string,
   replace: string
 ): FunctionExpr;
@@ -5145,13 +5155,13 @@ export function replaceAll(
  * replaceAll(field("message"), field("findField"), field("replaceField"));
  * ```
  *
- * @param value The expression representing the string to perform the replacement on.
+ * @param stringExpression The expression representing the string to perform the replacement on.
  * @param find The expression representing the substring to search for.
  * @param replace The expression representing the substring to replace all occurrences of 'find' with.
  * @return A new {@code Expr} representing the string with all occurrences replaced.
  */
 export function replaceAll(
-  value: Expr,
+  stringExpression: Expr,
   find: Expr,
   replace: Expr
 ): FunctionExpr;
@@ -5423,7 +5433,7 @@ export function regexContains(
  *
  * @param fieldName The name of the field containing the string.
  * @param pattern The regular expression to use for the match.
- * @return A new {@code Expr} representing the regular expression match.
+ * @return A new {@code Expr} representing the regular expression match comparison.
  */
 export function regexMatch(fieldName: string, pattern: string): BooleanExpr;
 
@@ -5439,7 +5449,7 @@ export function regexMatch(fieldName: string, pattern: string): BooleanExpr;
  *
  * @param fieldName The name of the field containing the string.
  * @param pattern The regular expression to use for the match.
- * @return A new {@code Expr} representing the regular expression match.
+ * @return A new {@code Expr} representing the regular expression match comparison.
  */
 export function regexMatch(fieldName: string, pattern: Expr): BooleanExpr;
 
@@ -5456,7 +5466,7 @@ export function regexMatch(fieldName: string, pattern: Expr): BooleanExpr;
  *
  * @param stringExpression The expression representing the string to match against.
  * @param pattern The regular expression to use for the match.
- * @return A new {@code Expr} representing the regular expression match.
+ * @return A new {@code Expr} representing the regular expression match comparison.
  */
 export function regexMatch(
   stringExpression: Expr,
@@ -5476,7 +5486,7 @@ export function regexMatch(
  *
  * @param stringExpression The expression representing the string to match against.
  * @param pattern The regular expression to use for the match.
- * @return A new {@code Expr} representing the regular expression match.
+ * @return A new {@code Expr} representing the regular expression match comparison.
  */
 export function regexMatch(stringExpression: Expr, pattern: Expr): BooleanExpr;
 export function regexMatch(
@@ -5498,7 +5508,7 @@ export function regexMatch(
  * strContains("description", "example");
  * ```
  *
- * @param fieldName The name of the field containing the string.
+ * @param fieldName The name of the field to perform the comparison on.
  * @param substring The substring to search for.
  * @return A new {@code Expr} representing the 'contains' comparison.
  */
@@ -5514,7 +5524,7 @@ export function strContains(fieldName: string, substring: string): BooleanExpr;
  * strContains("description", field("keyword"));
  * ```
  *
- * @param fieldName The name of the field containing the string.
+ * @param fieldName The name of the field to perform the comparison on.
  * @param substring The expression representing the substring to search for.
  * @return A new {@code Expr} representing the 'contains' comparison.
  */
@@ -5716,7 +5726,7 @@ export function endsWith(
  * toLower("name");
  * ```
  *
- * @param fieldName The name of the field containing the string.
+ * @param fieldName The name of the field containing the string to convert to lowercase.
  * @return A new {@code Expr} representing the lowercase string.
  */
 export function toLower(fieldName: string): FunctionExpr;
@@ -5749,7 +5759,7 @@ export function toLower(expr: Expr | string): FunctionExpr {
  * toUpper("title");
  * ```
  *
- * @param fieldName The name of the field containing the string.
+ * @param fieldName The name of the field containing the string to convert to uppercase.
  * @return A new {@code Expr} representing the uppercase string.
  */
 export function toUpper(fieldName: string): FunctionExpr;
@@ -5782,7 +5792,7 @@ export function toUpper(expr: Expr | string): FunctionExpr {
  * trim("userInput");
  * ```
  *
- * @param fieldName The name of the field containing the string.
+ * @param fieldName The name of the field containing the string to trim.
  * @return A new {@code Expr} representing the trimmed string.
  */
 export function trim(fieldName: string): FunctionExpr;
@@ -5816,8 +5826,8 @@ export function trim(expr: Expr | string): FunctionExpr {
  * ```
  *
  * @param fieldName The field name containing the initial string value.
- * @param secondString An expression or string literal to concatenate.
- * @param otherStrings Optional additional expressions or literals (typically strings) to concatenate.
+ * @param secondString A string expression or string literal to concatenate.
+ * @param otherStrings Optional additional string expressions or string literals to concatenate.
  * @return A new {@code Expr} representing the concatenated string.
  */
 export function strConcat(
@@ -5835,9 +5845,9 @@ export function strConcat(
  * strConcat(field("firstName"), " ", field("lastName"));
  * ```
  *
- * @param firstString The initial string expression to concatenate to.
- * @param secondString An expression or string literal to concatenate.
- * @param otherStrings Optional additional expressions or literals (typically strings) to concatenate.
+ * @param firstString The expression representing the initial string value.
+ * @param secondString A string expression or string literal to concatenate.
+ * @param otherStrings Optional additional string expressions or string literals to concatenate.
  * @return A new {@code Expr} representing the concatenated string.
  */
 export function strConcat(
@@ -5867,10 +5877,10 @@ export function strConcat(
  * ```
  *
  * @param fieldName The field name of the map field.
- * @param subField The key to access in the map.
+ * @param key The key to access in the map.
  * @return A new {@code Expr} representing the value associated with the given key in the map.
  */
-export function mapGet(fieldName: string, subField: string): FunctionExpr;
+export function mapGet(fieldName: string, key: string): FunctionExpr;
 
 /**
  * @beta
@@ -6336,7 +6346,7 @@ export function euclideanDistance(
 /**
  * @beta
  *
- * Creates an expression that calculates the length of a Firestore Vector.
+ * Creates an expression that calculates the length (dimension) of a Firestore Vector.
  *
  * ```typescript
  * // Get the vector length (dimension) of the field 'embedding'.
@@ -6344,22 +6354,22 @@ export function euclideanDistance(
  * ```
  *
  * @param vectorExpression The expression representing the Firestore Vector.
- * @return A new {@code Expr} representing the length of the array.
+ * @return A new {@code Expr} representing the length of the vector.
  */
 export function vectorLength(vectorExpression: Expr): FunctionExpr;
 
 /**
  * @beta
  *
- * Creates an expression that calculates the length of a Firestore Vector represented by a field.
+ * Creates an expression that calculates the length (dimension) of a Firestore Vector represented by a field.
  *
  * ```typescript
  * // Get the vector length (dimension) of the field 'embedding'.
  * vectorLength("embedding");
  * ```
  *
- * @param fieldName The name of the field representing the Firestore Vector.
- * @return A new {@code Expr} representing the length of the array.
+ * @param fieldName The name of the field containing the Firestore Vector.
+ * @return A new {@code Expr} representing the length (dimension) of the vector.
  */
 export function vectorLength(fieldName: string): FunctionExpr;
 export function vectorLength(expr: Expr | string): FunctionExpr {
@@ -6585,7 +6595,7 @@ export function timestampToUnixSeconds(expr: Expr | string): FunctionExpr {
  * ```
  *
  * @param timestamp The expression representing the timestamp.
- * @param unit The expression evaluates to unit of time, must be one of 'microsecond', 'millisecond', 'second', 'minute', 'hour', 'day'.
+ * @param unit The expression evaluates to unit of time. Valid units include 'microsecond', 'millisecond', 'second', 'minute', 'hour', 'day'.
  * @param amount The expression evaluates to amount of the unit.
  * @return A new {@code Expr} representing the resulting timestamp.
  */
@@ -6626,7 +6636,7 @@ export function timestampAdd(
  * timestampAdd("timestamp", "day", 1);
  * ```
  *
- * @param fieldName The name of the field representing the timestamp.
+ * @param fieldName The name of the field that contains the timestamp.
  * @param unit The unit of time to add (e.g., "day", "hour").
  * @param amount The amount of time to add.
  * @return A new {@code Expr} representing the resulting timestamp.
@@ -6665,7 +6675,7 @@ export function timestampAdd(
  * ```
  *
  * @param timestamp The expression representing the timestamp.
- * @param unit The expression evaluates to unit of time, must be one of 'microsecond', 'millisecond', 'second', 'minute', 'hour', 'day'.
+ * @param unit The expression evaluates to unit of time. Valid units include 'microsecond', 'millisecond', 'second', 'minute', 'hour', 'day'.
  * @param amount The expression evaluates to amount of the unit.
  * @return A new {@code Expr} representing the resulting timestamp.
  */
@@ -6706,7 +6716,7 @@ export function timestampSub(
  * timestampSub("timestamp", "day", 1);
  * ```
  *
- * @param fieldName The name of the field representing the timestamp.
+ * @param fieldName The name of the field that contains the timestamp.
  * @param unit The unit of time to subtract (e.g., "day", "hour").
  * @param amount The amount of time to subtract.
  * @return A new {@code Expr} representing the resulting timestamp.