diff --git a/docs/reference/query-languages/esql/_snippets/commands/layout/stats-by.md b/docs/reference/query-languages/esql/_snippets/commands/layout/stats-by.md
index 4f694b9db59d0..89fcd89a4dff9 100644
--- a/docs/reference/query-languages/esql/_snippets/commands/layout/stats-by.md
+++ b/docs/reference/query-languages/esql/_snippets/commands/layout/stats-by.md
@@ -51,6 +51,10 @@ The following [aggregation functions](/reference/query-languages/esql/functions-
 :::{include} ../../lists/aggregation-functions.md
 :::
 
+When `STATS` is used under the [`TS`](/reference/query-languages/esql/commands/ts.md) source command,
+[time series aggregation functions](/reference/query-languages/esql/functions-operators/time-series-aggregation-functions.md)
+are also supported.
+
 The following [grouping functions](/reference/query-languages/esql/functions-operators/grouping-functions.md) are supported:
 
 :::{include} ../../lists/grouping-functions.md
diff --git a/docs/reference/query-languages/esql/_snippets/functions/description/rate.md b/docs/reference/query-languages/esql/_snippets/functions/description/rate.md
index 0de1312951f82..25471c866493c 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/description/rate.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/description/rate.md
@@ -2,5 +2,5 @@
 
 **Description**
 
-Calculates the rate of a counter field.
+Calculates the per-second average rate of increase of a [counter](docs-content://manage-data/data-store/data-streams/time-series-data-stream-tsds.md#time-series-metric). Rate calculations account for breaks in monotonicity, such as counter resets when a service restarts, and extrapolate values within each bucketed time interval. Rate is the most appropriate aggregate function for counters. It is only allowed in a [STATS](/reference/query-languages/esql/commands/stats-by.md) command under a [`TS`](/reference/query-languages/esql/commands/ts.md) source command, to be properly applied per time series.
 
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/absent_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/absent_over_time.md
index 38d6822dab0b6..cd13f23decfc4 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/absent_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/absent_over_time.md
@@ -3,6 +3,7 @@
 ## `ABSENT_OVER_TIME` [esql-absent_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/avg_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/avg_over_time.md
index 88acfef1f7f5d..f01a5a76fd27b 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/avg_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/avg_over_time.md
@@ -3,6 +3,7 @@
 ## `AVG_OVER_TIME` [esql-avg_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/count_distinct_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/count_distinct_over_time.md
index 2bc1e286cab68..2d1c0f5e0384d 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/count_distinct_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/count_distinct_over_time.md
@@ -3,6 +3,7 @@
 ## `COUNT_DISTINCT_OVER_TIME` [esql-count_distinct_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/count_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/count_over_time.md
index 292dff0e10e06..3040e7c0f596a 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/count_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/count_over_time.md
@@ -3,6 +3,7 @@
 ## `COUNT_OVER_TIME` [esql-count_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/first_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/first_over_time.md
index 50462fef0d1ab..e77911f4b7627 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/first_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/first_over_time.md
@@ -3,6 +3,7 @@
 ## `FIRST_OVER_TIME` [esql-first_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/last_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/last_over_time.md
index 0fdb3f6c06912..1a0a2251e17de 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/last_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/last_over_time.md
@@ -3,6 +3,7 @@
 ## `LAST_OVER_TIME` [esql-last_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/max_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/max_over_time.md
index 4d0732a26cded..0cec101fd928b 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/max_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/max_over_time.md
@@ -3,6 +3,7 @@
 ## `MAX_OVER_TIME` [esql-max_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/min_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/min_over_time.md
index 3644fde260d58..3a9e14fd8901b 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/min_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/min_over_time.md
@@ -3,6 +3,7 @@
 ## `MIN_OVER_TIME` [esql-min_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/present_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/present_over_time.md
index 04fb44bc9f672..d7f35b92b46b8 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/present_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/present_over_time.md
@@ -3,6 +3,7 @@
 ## `PRESENT_OVER_TIME` [esql-present_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/rate.md b/docs/reference/query-languages/esql/_snippets/functions/layout/rate.md
index fc62158b7213a..f27eddd78521b 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/rate.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/rate.md
@@ -3,6 +3,7 @@
 ## `RATE` [esql-rate]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/functions/layout/sum_over_time.md b/docs/reference/query-languages/esql/_snippets/functions/layout/sum_over_time.md
index 647ff06f7181e..db9dd9936f0bf 100644
--- a/docs/reference/query-languages/esql/_snippets/functions/layout/sum_over_time.md
+++ b/docs/reference/query-languages/esql/_snippets/functions/layout/sum_over_time.md
@@ -3,6 +3,7 @@
 ## `SUM_OVER_TIME` [esql-sum_over_time]
 ```{applies_to}
 stack: preview 9.2.0
+serverless: preview
 ```
 
 **Syntax**
diff --git a/docs/reference/query-languages/esql/_snippets/lists/time-series-aggregation-functions.md b/docs/reference/query-languages/esql/_snippets/lists/time-series-aggregation-functions.md
index 17db563e9dade..802efda2a8042 100644
--- a/docs/reference/query-languages/esql/_snippets/lists/time-series-aggregation-functions.md
+++ b/docs/reference/query-languages/esql/_snippets/lists/time-series-aggregation-functions.md
@@ -1,11 +1,11 @@
-* [preview] [`ABSENT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-absent_over_time)
-* [preview] [`AVG_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-avg_over_time)
-* [preview] [`COUNT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-count_over_time)
-* [preview] [`COUNT_DISTINCT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-count_distinct_over_time)
-* [preview] [`FIRST_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-first_over_time)
-* [preview] [`LAST_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-last_over_time)
-* [preview] [`MAX_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-max_over_time)
-* [preview] [`MIN_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-min_over_time)
-* [preview] [`PRESENT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-present_over_time)
-* [preview] [`RATE`](../../functions-operators/time-series-aggregation-functions.md#esql-rate)
-* [preview] [`SUM_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-sum_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`ABSENT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-absent_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`AVG_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-avg_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`COUNT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-count_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`COUNT_DISTINCT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-count_distinct_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`FIRST_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-first_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`LAST_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-last_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`MAX_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-max_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`MIN_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-min_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`PRESENT_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-present_over_time)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`RATE`](../../functions-operators/time-series-aggregation-functions.md#esql-rate)
+* {applies_to}`stack: preview 9.2` {applies_to}`serverless: preview` [`SUM_OVER_TIME`](../../functions-operators/time-series-aggregation-functions.md#esql-sum_over_time)
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/absent_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/absent_over_time.json
index 879918c653dda..52f43004884ae 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/absent_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/absent_over_time.json
@@ -224,6 +224,6 @@
   "examples" : [
     "TS k8s\n| WHERE cluster == \"prod\" AND pod == \"two\"\n| STATS events_received = max(absent_over_time(events_received)) BY pod, time_bucket = tbucket(2 minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/avg_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/avg_over_time.json
index 5f449bb6459f5..71c81f9e6713b 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/avg_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/avg_over_time.json
@@ -44,6 +44,6 @@
   "examples" : [
     "TS k8s\n| STATS max_cost=max(avg_over_time(network.cost)) BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/count_distinct_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/count_distinct_over_time.json
index fd994aa15537e..0d3204f99270b 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/count_distinct_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/count_distinct_over_time.json
@@ -668,6 +668,6 @@
   "examples" : [
     "TS k8s\n| STATS distincts=count_distinct(count_distinct_over_time(network.cost)),\n        distincts_imprecise=count_distinct(count_distinct_over_time(network.cost, 100))\n  BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/count_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/count_over_time.json
index efdc885ee1265..219ebe563b2c2 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/count_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/count_over_time.json
@@ -224,6 +224,6 @@
   "examples" : [
     "TS k8s\n| STATS count=count(count_over_time(network.cost))\n  BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/first_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/first_over_time.json
index 052b2a65e223c..e2cc52285e8e9 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/first_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/first_over_time.json
@@ -44,6 +44,6 @@
   "examples" : [
     "TS k8s\n| STATS max_cost=max(first_over_time(network.cost)) BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/last_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/last_over_time.json
index 0c732d51ea66b..48f96880e0001 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/last_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/last_over_time.json
@@ -44,6 +44,6 @@
   "examples" : [
     "TS k8s\n| STATS max_cost=max(last_over_time(network.cost)) BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/max_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/max_over_time.json
index 340e6543a4e3f..b55684e8094e4 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/max_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/max_over_time.json
@@ -140,6 +140,6 @@
   "examples" : [
     "TS k8s\n| STATS cost=sum(max_over_time(network.cost)) BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/min_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/min_over_time.json
index ab34295c27765..8bc00fd660299 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/min_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/min_over_time.json
@@ -140,6 +140,6 @@
   "examples" : [
     "TS k8s\n| STATS cost=sum(min_over_time(network.cost)) BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/present_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/present_over_time.json
index 87a66d4a49ef5..844663d378495 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/present_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/present_over_time.json
@@ -224,6 +224,6 @@
   "examples" : [
     "TS k8s\n| WHERE cluster == \"prod\" AND pod == \"two\"\n| STATS events_received = max(present_over_time(events_received)) BY pod, time_bucket = tbucket(2 minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/rate.json b/docs/reference/query-languages/esql/kibana/definition/functions/rate.json
index 751619fb00472..9468b7f113ec4 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/rate.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/rate.json
@@ -2,7 +2,7 @@
   "comment" : "This is generated by ESQL's AbstractFunctionTestCase. Do not edit it. See ../README.md for how to regenerate it.",
   "type" : "time_series_agg",
   "name" : "rate",
-  "description" : "Calculates the rate of a counter field.",
+  "description" : "Calculates the per-second average rate of increase of a counter. Rate calculations account for breaks in monotonicity, such as counter resets when a service restarts, and extrapolate values within each bucketed time interval. Rate is the most appropriate aggregate function for counters. It is only allowed in a STATS command under a `TS` source command, to be properly applied per time series.",
   "signatures" : [
     {
       "params" : [
@@ -44,6 +44,6 @@
   "examples" : [
     "TS k8s\n| STATS max(rate(network.total_bytes_in)) BY time_bucket = bucket(@timestamp,5minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/definition/functions/sum_over_time.json b/docs/reference/query-languages/esql/kibana/definition/functions/sum_over_time.json
index 2888b2caded55..85cec3677bc31 100644
--- a/docs/reference/query-languages/esql/kibana/definition/functions/sum_over_time.json
+++ b/docs/reference/query-languages/esql/kibana/definition/functions/sum_over_time.json
@@ -44,6 +44,6 @@
   "examples" : [
     "TS k8s\n| STATS sum_cost=sum(sum_over_time(network.cost)) BY cluster, time_bucket = bucket(@timestamp,1minute)"
   ],
-  "preview" : false,
+  "preview" : true,
   "snapshot_only" : false
 }
diff --git a/docs/reference/query-languages/esql/kibana/docs/functions/rate.md b/docs/reference/query-languages/esql/kibana/docs/functions/rate.md
index 66cbfffb695ab..bf8504018d01b 100644
--- a/docs/reference/query-languages/esql/kibana/docs/functions/rate.md
+++ b/docs/reference/query-languages/esql/kibana/docs/functions/rate.md
@@ -1,7 +1,7 @@
 % This is generated by ESQL's AbstractFunctionTestCase. Do not edit it. See ../README.md for how to regenerate it.
 
 ### RATE
-Calculates the rate of a counter field.
+Calculates the per-second average rate of increase of a [counter](docs-content://manage-data/data-store/data-streams/time-series-data-stream-tsds.md#time-series-metric). Rate calculations account for breaks in monotonicity, such as counter resets when a service restarts, and extrapolate values within each bucketed time interval. Rate is the most appropriate aggregate function for counters. It is only allowed in a [STATS](https://www.elastic.co/docs/reference/query-languages/esql/commands/stats-by) command under a [`TS`](https://www.elastic.co/docs/reference/query-languages/esql/commands/ts) source command, to be properly applied per time series.
 
 ```esql
 TS k8s
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AbsentOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AbsentOverTime.java
index bc0e6eff72ec3..072d98a461855 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AbsentOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AbsentOverTime.java
@@ -41,6 +41,7 @@ public class AbsentOverTime extends TimeSeriesAggregateFunction {
         returnType = { "boolean" },
         description = "Calculates the absence of a field in the output result over time range.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "absent_over_time") }
     )
     public AbsentOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AvgOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AvgOverTime.java
index b1c92c3f6dafd..bfe68696e5806 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AvgOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AvgOverTime.java
@@ -43,6 +43,7 @@ public class AvgOverTime extends TimeSeriesAggregateFunction implements Surrogat
         description = "Calculates the average over time of a numeric field.",
         type = FunctionType.TIME_SERIES_AGGREGATE,
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "avg_over_time") }
     )
     public AvgOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountDistinctOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountDistinctOverTime.java
index f1cce3c144f4f..2396e4e69bad8 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountDistinctOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountDistinctOverTime.java
@@ -42,6 +42,7 @@ public class CountDistinctOverTime extends TimeSeriesAggregateFunction implement
         returnType = { "long" },
         description = "Calculates the count of distinct values over time for a field.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "count_distinct_over_time") }
     )
     public CountDistinctOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountOverTime.java
index c392e7438620b..0d75c1f082f74 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountOverTime.java
@@ -41,6 +41,7 @@ public class CountOverTime extends TimeSeriesAggregateFunction {
         returnType = { "long" },
         description = "Calculates the count over time value of a field.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "count_over_time") }
     )
     public CountOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Delta.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Delta.java
index 4e1ae09f936e8..d6455990299a4 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Delta.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Delta.java
@@ -45,7 +45,8 @@ public class Delta extends TimeSeriesAggregateFunction implements OptionalArgume
         type = FunctionType.TIME_SERIES_AGGREGATE,
         returnType = { "double" },
         description = "Calculates the absolute change of a gauge field in a time window.",
-        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.UNAVAILABLE) },
+        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command"
     )
     public Delta(Source source, @Param(name = "field", type = { "long", "integer", "double" }) Expression field) {
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/FirstOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/FirstOverTime.java
index 908d4bd97cc32..ca76d521142c7 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/FirstOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/FirstOverTime.java
@@ -53,6 +53,7 @@ public class FirstOverTime extends TimeSeriesAggregateFunction implements Option
         returnType = { "long", "integer", "double" },
         description = "Calculates the earliest value of a field, where recency determined by the `@timestamp` field.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "first_over_time") }
     )
     public FirstOverTime(Source source, @Param(name = "field", type = { "long", "integer", "double" }) Expression field) {
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Idelta.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Idelta.java
index 0553a265b0572..bfd70f17df693 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Idelta.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Idelta.java
@@ -47,7 +47,8 @@ public class Idelta extends TimeSeriesAggregateFunction implements OptionalArgum
         description = "Calculates the idelta of a gauge. idelta is the absolute change between the last two data points ("
             + "it ignores all but the last two data points in each time period). "
             + "This function is very similar to delta, but is more responsive to recent changes.",
-        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") }
+        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true
     )
     public Idelta(Source source, @Param(name = "field", type = { "long", "integer", "double" }) Expression field) {
         this(source, field, new UnresolvedAttribute(source, "@timestamp"));
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Increase.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Increase.java
index e490ffad181ec..cfdb3123685b6 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Increase.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Increase.java
@@ -50,7 +50,8 @@ public class Increase extends TimeSeriesAggregateFunction implements OptionalArg
         type = FunctionType.TIME_SERIES_AGGREGATE,
         returnType = { "double" },
         description = "Calculates the absolute increase of a counter field in a time window.",
-        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") }
+        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true
     )
     public Increase(
         Source source,
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Irate.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Irate.java
index 2195e814e9d4a..3705b3e0a496f 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Irate.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Irate.java
@@ -48,6 +48,7 @@ public class Irate extends TimeSeriesAggregateFunction implements OptionalArgume
             + "it ignores all but the last two data points in each time period). "
             + "This function is very similar to rate, but is more responsive to recent changes in the rate of increase.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "irate") }
     )
     public Irate(Source source, @Param(name = "field", type = { "counter_long", "counter_integer", "counter_double" }) Expression field) {
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/LastOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/LastOverTime.java
index 07c7dc988dcba..ccb9695339891 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/LastOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/LastOverTime.java
@@ -54,6 +54,7 @@ public class LastOverTime extends TimeSeriesAggregateFunction implements Optiona
         returnType = { "long", "integer", "double", "_tsid" },
         description = "Calculates the latest value of a field, where recency determined by the `@timestamp` field.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "last_over_time") }
     )
     public LastOverTime(Source source, @Param(name = "field", type = { "long", "integer", "double", "_tsid" }) Expression field) {
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MaxOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MaxOverTime.java
index 5550d8709aaeb..2bc011eecfc36 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MaxOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MaxOverTime.java
@@ -41,6 +41,7 @@ public class MaxOverTime extends TimeSeriesAggregateFunction {
         description = "Calculates the maximum over time value of a field.",
         type = FunctionType.TIME_SERIES_AGGREGATE,
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "max_over_time") }
     )
     public MaxOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MinOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MinOverTime.java
index 56d3f66239c93..3258688cb1844 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MinOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/MinOverTime.java
@@ -41,6 +41,7 @@ public class MinOverTime extends TimeSeriesAggregateFunction {
         description = "Calculates the minimum over time value of a field.",
         type = FunctionType.TIME_SERIES_AGGREGATE,
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "min_over_time") }
     )
     public MinOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/PresentOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/PresentOverTime.java
index d27d172ae6dfc..805a4b09d6da5 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/PresentOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/PresentOverTime.java
@@ -41,6 +41,7 @@ public class PresentOverTime extends TimeSeriesAggregateFunction {
         returnType = { "boolean" },
         description = "Calculates the presence of a field in the output result over time range.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "present_over_time") }
     )
     public PresentOverTime(
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Rate.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Rate.java
index c9e4a2eb68e15..a3406959931be 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Rate.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Rate.java
@@ -44,10 +44,17 @@ public class Rate extends TimeSeriesAggregateFunction implements OptionalArgumen
     @FunctionInfo(
         type = FunctionType.TIME_SERIES_AGGREGATE,
         returnType = { "double" },
-        description = "Calculates the rate of a counter field.",
+        description = "Calculates the per-second average rate of increase of a"
+            + " [counter](docs-content://manage-data/data-store/data-streams/time-series-data-stream-tsds.md#time-series-metric). "
+            + "Rate calculations account for breaks in monotonicity, such as counter resets when a service restarts, and extrapolate "
+            + "values within each bucketed time interval. Rate is the most appropriate aggregate function for counters. It is only allowed "
+            + "in a [STATS](/reference/query-languages/esql/commands/stats-by.md) command under a "
+            + "[`TS`](/reference/query-languages/esql/commands/ts.md) source command, to be properly applied per time series.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "rate") }
     )
+
     public Rate(Source source, @Param(name = "field", type = { "counter_long", "counter_integer", "counter_double" }) Expression field) {
         this(source, field, new UnresolvedAttribute(source, "@timestamp"));
     }
diff --git a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/SumOverTime.java b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/SumOverTime.java
index 14b125e6c7b87..c8968a63b38dd 100644
--- a/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/SumOverTime.java
+++ b/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/SumOverTime.java
@@ -41,6 +41,7 @@ public class SumOverTime extends TimeSeriesAggregateFunction {
         description = "Calculates the sum over time value of a field.",
         type = FunctionType.TIME_SERIES_AGGREGATE,
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW, version = "9.2.0") },
+        preview = true,
         examples = { @Example(file = "k8s-timeseries", tag = "sum_over_time") }
     )
     public SumOverTime(