diff --git a/pkg/providers/anthropic/provider.go b/pkg/providers/anthropic/provider.go
index 242ded1757..d4ceaab2cd 100644
--- a/pkg/providers/anthropic/provider.go
+++ b/pkg/providers/anthropic/provider.go
@@ -180,6 +180,10 @@ func buildParams(
 					blocks = append(blocks, anthropic.NewTextBlock(msg.Content))
 				}
 				for _, tc := range msg.ToolCalls {
+					// Skip tool calls with empty names to avoid API errors
+					if tc.Name == "" {
+						continue
+					}
 					args := tc.Arguments
 					if args == nil && tc.Function != nil && tc.Function.Arguments != "" {
 						if err := json.Unmarshal([]byte(tc.Function.Arguments), &args); err != nil {