diff --git a/temporal/api/workflow/v1/message.proto b/temporal/api/workflow/v1/message.proto
index 8f191d35e..f57130b26 100644
--- a/temporal/api/workflow/v1/message.proto
+++ b/temporal/api/workflow/v1/message.proto
@@ -100,6 +100,9 @@ message PendingWorkflowTaskInfo {
     google.protobuf.Timestamp original_scheduled_time = 3 [(gogoproto.stdtime) = true];
     google.protobuf.Timestamp started_time = 4 [(gogoproto.stdtime) = true];
     int32 attempt = 5;
+    // If set, this pending workflow task will need to be (or is currently being) handled by a
+    // a worker using this build id.
+    string will_use_build_id = 6;
 }
 
 message ResetPoints {
diff --git a/temporal/api/workflowservice/v1/request_response.proto b/temporal/api/workflowservice/v1/request_response.proto
index 88f9f7569..272c1cbf0 100644
--- a/temporal/api/workflowservice/v1/request_response.proto
+++ b/temporal/api/workflowservice/v1/request_response.proto
@@ -769,6 +769,9 @@ message QueryWorkflowResponse {
 message DescribeWorkflowExecutionRequest {
     string namespace = 1;
     temporal.api.common.v1.WorkflowExecution execution = 2;
+    // If set, the response will include which build id shall be used to process the pending
+    // workflow task, if any.
+    bool include_pending_workflow_task_build_id = 3;
 }
 
 message DescribeWorkflowExecutionResponse {
@@ -1058,6 +1061,12 @@ message GetWorkerBuildIdOrderingRequest {
     // Limits how many compatible sets will be returned. Specify 1 to only return the current
     // default major version set. 0 returns all sets.
     int32 max_sets = 3;
+    // If set, the response will include information about worker versions which are ready to be
+    // retired.
+    bool include_retirement_candidates = 4;
+    // If set, the response will include information about which versions have open workflows, and
+    // whether or not there are currently polling workers who are compatible with those versions.
+    bool include_poller_compatability = 5;
 }
 message GetWorkerBuildIdOrderingResponse {
     // Major version sets, in order from oldest to newest. The last element of the list will always
@@ -1066,6 +1075,32 @@ message GetWorkerBuildIdOrderingResponse {
     //
     // There may be fewer sets returned than exist, if the request chose to limit this response.
     repeated temporal.api.taskqueue.v1.CompatibleVersionSet major_version_sets = 1;
+
+    message RetirementCandidate {
+        // The worker build id which is ready for retirement
+        string build_id = 1;
+        // If true, there are no open *or* closed workflows, meaning there is no reason at all
+        // to keep the worker alive, not even to service queries on closed workflows. If not true,
+        // then there are no open workflows, but some closed ones.
+        bool no_closed_workflows = 2;
+        // Currently polling workers who match the build id ready for retirement
+        repeated temporal.api.taskqueue.v1.PollerInfo pollers = 3;
+    }
+
+    // A list of workers who are still live and polling the task queue, but may no longer be needed
+    // to make progress on open workflows.
+    repeated RetirementCandidate retirement_candidates = 2;
+
+    message VersionsWithCompatiblePollers {
+        // The latest build id which completed a workflow task on some open workflow
+        string most_recent_build_id = 1;
+        // Currently polling workers who are compatible with `most_recent_build_id`.
+        repeated temporal.api.taskqueue.v1.PollerInfo pollers = 2;
+    }
+
+    // A list of versions and pollers who are capable of processing tasks at that version (if any)
+    // for which there are currently open workflows.
+    repeated VersionsWithCompatiblePollers active_versions_and_pollers = 3;
 }
 
 // (-- api-linter: core::0134=disabled