diff --git a/apps/web/src/components/BranchToolbar.tsx b/apps/web/src/components/BranchToolbar.tsx
index d36eabc3cec5578a2782bf743249ea47616c6c06..b2840cfadd0ee177f2efa46009eaccd38c6abfa1 100644
--- a/apps/web/src/components/BranchToolbar.tsx
+++ b/apps/web/src/components/BranchToolbar.tsx
@@ -53,6 +53,7 @@ import {
   MenuTrigger,
 } from "./ui/menu";
 import { Separator } from "./ui/separator";
+import { Tooltip, TooltipPopup, TooltipTrigger } from "./ui/tooltip";
 import { ComposerSurface } from "./chat/ComposerSurface";
 import { useComposerMenuProps } from "./chat/composerEventScope";
 import { measureRestingComposerControls } from "./chat/restingComposerControlsMeasurement";
@@ -137,22 +138,35 @@ const MobileRunContextSelector = memo(function MobileRunContextSelector({
       ? resolveEnvModeLabel("worktree")
       : resolveCurrentWorkspaceLabel(activeWorktreePath);
   const isLocked = envLocked || envModeLocked;
+  const workspaceIcon = (
+    <Tooltip>
+      <TooltipTrigger render={<span className="inline-flex shrink-0" />}>
+        <WorkspaceIcon className={cn("size-3 shrink-0", showEnvironmentIndicator && "mx-0!")} />
+      </TooltipTrigger>
+      <TooltipPopup>{workspaceLabel}</TooltipPopup>
+    </Tooltip>
+  );
   const icon = showEnvironmentIndicator ? (
     // Button's base styles apply `-mx-0.5` to descendant SVGs, which eats 4px
     // out of whatever gap we set. mx-0! cancels that so gap-0.5 reads as 2px.
     <span className="inline-flex shrink-0 items-center gap-0.5">
-      {autoEnvironmentLabel ? (
-        <ScaleIcon className="size-3 shrink-0 mx-0!" aria-hidden="true" />
-      ) : (
-        <EnvironmentMachineIcon
-          kind={activeEnvironment?.machine ?? "server"}
-          className="size-3 shrink-0 mx-0!"
-        />
-      )}
-      <WorkspaceIcon className="size-3 shrink-0 mx-0!" />
+      <Tooltip>
+        <TooltipTrigger render={<span className="inline-flex shrink-0" />}>
+          {autoEnvironmentLabel ? (
+            <ScaleIcon className="size-3 shrink-0 mx-0!" aria-hidden="true" />
+          ) : (
+            <EnvironmentMachineIcon
+              kind={activeEnvironment?.machine ?? "server"}
+              className="size-3 shrink-0 mx-0!"
+            />
+          )}
+        </TooltipTrigger>
+        <TooltipPopup>{autoEnvironmentLabel ?? activeEnvironment?.label ?? "Run on"}</TooltipPopup>
+      </Tooltip>
+      {workspaceIcon}
     </span>
   ) : (
-    <WorkspaceIcon className="size-3 shrink-0" />
+    workspaceIcon
   );
   const triggerContent = (
     <>
diff --git a/apps/web/src/components/BranchToolbarEnvModeSelector.tsx b/apps/web/src/components/BranchToolbarEnvModeSelector.tsx
index b29c77cb378d4819ce1aa98e3152333559fc2729..c1c3487dbadcdc519fde11357135a8533333ba75 100644
--- a/apps/web/src/components/BranchToolbarEnvModeSelector.tsx
+++ b/apps/web/src/components/BranchToolbarEnvModeSelector.tsx
@@ -17,6 +17,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from "./ui/select";
+import { Tooltip, TooltipPopup, TooltipTrigger } from "./ui/tooltip";
 
 const PREVIOUS_WORKTREE_SELECT_VALUE = "previous-worktree";
 
@@ -52,27 +53,31 @@ export const BranchToolbarEnvModeSelector = memo(function BranchToolbarEnvModeSe
 
   if (envLocked) {
     return (
-      <span
-        className="inline-flex h-7 min-w-0 items-center gap-1 border border-transparent px-[calc(--spacing(2)-1px)] font-normal text-muted-foreground/70 text-xs sm:h-6"
-        data-composer-context-control
-      >
-        {activeWorktreePath ? (
-          <FolderGitIcon className="size-3 shrink-0" />
-        ) : (
-          <FolderIcon className="size-3 shrink-0" />
-        )}
-        <span
-          data-composer-label
-          className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
+      <Tooltip>
+        <TooltipTrigger
+          render={<span />}
+          className="inline-flex h-7 min-w-0 items-center gap-1 border border-transparent px-[calc(--spacing(2)-1px)] font-normal text-muted-foreground/70 text-xs sm:h-6"
+          data-composer-context-control
         >
+          {activeWorktreePath ? (
+            <FolderGitIcon className="size-3 shrink-0" />
+          ) : (
+            <FolderIcon className="size-3 shrink-0" />
+          )}
           <span
-            data-composer-label-motion
-            className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            data-composer-label
+            className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
           >
-            {resolveLockedWorkspaceLabel(activeWorktreePath)}
+            <span
+              data-composer-label-motion
+              className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            >
+              {resolveLockedWorkspaceLabel(activeWorktreePath)}
+            </span>
           </span>
-        </span>
-      </span>
+        </TooltipTrigger>
+        <TooltipPopup>{resolveLockedWorkspaceLabel(activeWorktreePath)}</TooltipPopup>
+      </Tooltip>
     );
   }
 
@@ -89,33 +94,44 @@ export const BranchToolbarEnvModeSelector = memo(function BranchToolbarEnvModeSe
       }}
       items={envModeItems}
     >
-      <SelectTrigger
-        variant="ghost"
-        size="xs"
-        className="min-w-0 shrink font-normal text-xs!"
-        aria-label="Workspace"
-        data-composer-shortcut="composer.workspace"
-        data-composer-context-control
-      >
-        {effectiveEnvMode === "worktree" ? (
-          <FolderGit2Icon className="size-3" />
-        ) : activeWorktreePath ? (
-          <FolderGitIcon className="size-3" />
-        ) : (
-          <FolderIcon className="size-3" />
-        )}
-        <span
-          data-composer-label
-          className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
+      <Tooltip>
+        <TooltipTrigger
+          render={
+            <SelectTrigger
+              variant="ghost"
+              size="xs"
+              className="min-w-0 shrink font-normal text-xs!"
+              aria-label="Workspace"
+              data-composer-shortcut="composer.workspace"
+              data-composer-context-control
+            />
+          }
         >
+          {effectiveEnvMode === "worktree" ? (
+            <FolderGit2Icon className="size-3" />
+          ) : activeWorktreePath ? (
+            <FolderGitIcon className="size-3" />
+          ) : (
+            <FolderIcon className="size-3" />
+          )}
           <span
-            data-composer-label-motion
-            className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            data-composer-label
+            className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
           >
-            <SelectValue />
+            <span
+              data-composer-label-motion
+              className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            >
+              <SelectValue />
+            </span>
           </span>
-        </span>
-      </SelectTrigger>
+        </TooltipTrigger>
+        <TooltipPopup>
+          {effectiveEnvMode === "worktree"
+            ? resolveEnvModeLabel("worktree")
+            : resolveCurrentWorkspaceLabel(activeWorktreePath)}
+        </TooltipPopup>
+      </Tooltip>
       <SelectPopup alignItemWithTrigger={false} {...composerFloatingLayerProps}>
         <SelectGroup>
           <SelectGroupLabel>Workspace</SelectGroupLabel>
diff --git a/apps/web/src/components/BranchToolbarEnvironmentSelector.tsx b/apps/web/src/components/BranchToolbarEnvironmentSelector.tsx
index 231e4b0d824d64a9a7624990b3431b05dc321fe5..a29bb92e83d00d5c52a5138a91f121eb3c623c88 100644
--- a/apps/web/src/components/BranchToolbarEnvironmentSelector.tsx
+++ b/apps/web/src/components/BranchToolbarEnvironmentSelector.tsx
@@ -14,6 +14,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from "./ui/select";
+import { Tooltip, TooltipPopup, TooltipTrigger } from "./ui/tooltip";
 
 interface BranchToolbarEnvironmentSelectorProps {
   autoEnvironmentLabel?: string | undefined;
@@ -59,26 +60,30 @@ export const BranchToolbarEnvironmentSelector = memo(function BranchToolbarEnvir
   // only thing in the strip.
   if (envLocked || onEnvironmentChange === undefined) {
     return (
-      <span
-        className="inline-flex h-7 min-w-0 max-w-full items-center gap-1 border border-transparent px-[calc(--spacing(2)-1px)] font-normal text-muted-foreground/70 text-xs sm:h-6"
-        data-composer-context-control
-      >
-        <EnvironmentMachineIcon
-          kind={activeEnvironment?.machine ?? "server"}
-          className="size-3 shrink-0"
-        />
-        <span
-          data-composer-label
-          className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
+      <Tooltip>
+        <TooltipTrigger
+          render={<span />}
+          className="inline-flex h-7 min-w-0 max-w-full items-center gap-1 border border-transparent px-[calc(--spacing(2)-1px)] font-normal text-muted-foreground/70 text-xs sm:h-6"
+          data-composer-context-control
         >
+          <EnvironmentMachineIcon
+            kind={activeEnvironment?.machine ?? "server"}
+            className="size-3 shrink-0"
+          />
           <span
-            data-composer-label-motion
-            className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            data-composer-label
+            className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
           >
-            {activeEnvironment?.label ?? "Run on"}
+            <span
+              data-composer-label-motion
+              className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            >
+              {activeEnvironment?.label ?? "Run on"}
+            </span>
           </span>
-        </span>
-      </span>
+        </TooltipTrigger>
+        <TooltipPopup>{activeEnvironment?.label ?? "Run on"}</TooltipPopup>
+      </Tooltip>
     );
   }
 
@@ -91,34 +96,41 @@ export const BranchToolbarEnvironmentSelector = memo(function BranchToolbarEnvir
       }
       items={environmentItems}
     >
-      <SelectTrigger
-        variant="ghost"
-        size="xs"
-        className="min-w-0 max-w-full font-normal text-xs!"
-        aria-label="Run on"
-        data-composer-shortcut="composer.host"
-        data-composer-context-control
-      >
-        {autoEnvironmentLabel ? (
-          <ScaleIcon className="size-3 shrink-0" aria-hidden="true" />
-        ) : (
-          <EnvironmentMachineIcon
-            kind={activeEnvironment?.machine ?? "server"}
-            className="size-3 shrink-0"
-          />
-        )}
-        <span
-          data-composer-label
-          className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
+      <Tooltip>
+        <TooltipTrigger
+          render={
+            <SelectTrigger
+              variant="ghost"
+              size="xs"
+              className="min-w-0 max-w-full font-normal text-xs!"
+              aria-label="Run on"
+              data-composer-shortcut="composer.host"
+              data-composer-context-control
+            />
+          }
         >
+          {autoEnvironmentLabel ? (
+            <ScaleIcon className="size-3 shrink-0" aria-hidden="true" />
+          ) : (
+            <EnvironmentMachineIcon
+              kind={activeEnvironment?.machine ?? "server"}
+              className="size-3 shrink-0"
+            />
+          )}
           <span
-            data-composer-label-motion
-            className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            data-composer-label
+            className="min-w-0 max-w-[240px] group-data-[compact]/composer-context:max-w-0"
           >
-            <SelectValue />
+            <span
+              data-composer-label-motion
+              className="block w-full min-w-0 max-w-[240px] truncate transition-opacity duration-180 ease-[cubic-bezier(0.32,0.72,0,1)] group-data-[compact]/composer-context:opacity-0 motion-reduce:transition-none"
+            >
+              <SelectValue />
+            </span>
           </span>
-        </span>
-      </SelectTrigger>
+        </TooltipTrigger>
+        <TooltipPopup>{autoEnvironmentLabel ?? activeEnvironment?.label ?? "Run on"}</TooltipPopup>
+      </Tooltip>
       <SelectPopup alignItemWithTrigger={false} {...composerFloatingLayerProps}>
         <SelectGroup>
           <SelectGroupLabel>Run on</SelectGroupLabel>