diff --git a/com.microsoft.copilot.eclipse.ui.test/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtilsTests.java b/com.microsoft.copilot.eclipse.ui.test/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtilsTests.java
index 4955f271..48d3588d 100644
--- a/com.microsoft.copilot.eclipse.ui.test/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtilsTests.java
+++ b/com.microsoft.copilot.eclipse.ui.test/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtilsTests.java
@@ -8,9 +8,14 @@
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.util.List;
+
 import org.junit.jupiter.api.Test;
 
 import com.microsoft.copilot.eclipse.core.lsp.protocol.CopilotModel;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.CopilotModel.CopilotModelCapabilities;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.CopilotModel.CopilotModelCapabilitiesLimits;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.CopilotModel.CopilotModelCapabilitiesSupports;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.CopilotScope;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.byok.ByokModel;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.byok.ByokModelCapabilities;
@@ -76,4 +81,15 @@ void testConvertByokModelToCopilotModel_preservesTokenLimits() {
     assertEquals(128000, result.getCapabilities().limits().maxInputTokens());
     assertEquals(16000, result.getCapabilities().limits().maxOutputTokens());
   }
+
+  @Test
+  void testResolveDefaultReasoningEffort_prefersMediumForClaudeModels() {
+    CopilotModel model = new CopilotModel();
+    model.setModelFamily("claude-3.7-sonnet");
+    model.setCapabilities(new CopilotModelCapabilities(
+        new CopilotModelCapabilitiesSupports(false, List.of("low", "medium", "high"), true),
+        new CopilotModelCapabilitiesLimits(null, null, null, null)));
+
+    assertEquals("medium", ModelUtils.resolveDefaultReasoningEffort(model));
+  }
 }
diff --git a/com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtils.java b/com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtils.java
index cec4a159..3533e651 100644
--- a/com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtils.java
+++ b/com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtils.java
@@ -78,9 +78,9 @@ public static String formatBillingMultiplier(double multiplier) {
   }
 
   /**
-   * Separator used between parts of the model picker suffix (e.g. "1M | High | $$$").
+   * Separator used between parts of the model picker suffix (e.g. "1M - High - $$$").
    */
-  private static final String SUFFIX_PART_SEPARATOR = " | ";
+  private static final String SUFFIX_PART_SEPARATOR = " - ";
 
   /**
    * Returns the display suffix for a model in the model picker.
@@ -196,8 +196,8 @@ public static String formatTokenCount(int tokens) {
   }
 
   /**
-   * Returns the default reasoning effort to use when the user has not made a selection. Prefers {@code high} for
-   * Claude models and {@code medium} for all others, falling back to the first entry in the supported list.
+    * Returns the default reasoning effort to use when the user has not made a selection. Prefers {@code medium} when
+    * it is supported, falling back to the first entry in the supported list.
    *
    * @param model the model
    * @return the default effort identifier, or {@code null} when none can be determined
@@ -207,11 +207,8 @@ public static String resolveDefaultReasoningEffort(CopilotModel model) {
     if (efforts.isEmpty()) {
       return null;
     }
-    String modelFamily = model.getModelFamily();
-    String preferred = modelFamily != null && modelFamily.toLowerCase(Locale.ROOT).startsWith("claude") ? "high"
-        : "medium";
     for (String effort : efforts) {
-      if (preferred.equalsIgnoreCase(effort)) {
+      if ("medium".equalsIgnoreCase(effort)) {
         return effort;
       }
     }