diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index ae02ea4..7575004 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -298,8 +298,13 @@ func run(ctx context.Context, cfg agentConfig, state state) error {
 			var result string
 			var resultBlocks []backend.ContentBlock
 			var isErr bool
+			streamed := false
 			if cfg.Exec != nil {
 					streamCtx := tools.WithOutputStream(ctx, func(data string) {
+						if !streamed {
+							emit(cfg, Event{Role: "tool", Name: tc.Name})
+							streamed = true
+						}
 						emit(cfg, Event{Role: "tool", Name: tc.Name, Content: data})
 					})
 					out, blocks, err := cfg.Exec(streamCtx, tc.Name, tc.Arguments)
@@ -349,7 +354,9 @@ func run(ctx context.Context, cfg agentConfig, state state) error {
 				if readSafe && !isErr {
 					resultCache.Store(tc.Name+"\x00"+string(tc.Arguments), result)
 				}
-				emit(cfg, Event{Role: "tool", Name: tc.Name, Content: result})
+				if !streamed {
+					emit(cfg, Event{Role: "tool", Name: tc.Name, Content: result})
+				}
 					tier := TierHot
 				if !isErr && cfg.ClassifyTier != nil {
 					tier = cfg.ClassifyTier(tc.Name, tc.Arguments)