diff --git a/toolsrv/client9p.go b/toolsrv/client9p.go
index 5ddb8f0..f632d59 100644
--- a/toolsrv/client9p.go
+++ b/toolsrv/client9p.go
@@ -148,9 +148,22 @@ func (c *Conn) CallTool(ctx context.Context, name string, args json.RawMessage)
 		return nil, fmt.Errorf("write: %w", err)
 	}
 
-	result, err := io.ReadAll(fid)
-	if err != nil {
-		return nil, fmt.Errorf("read: %w", err)
+	// Read result from offset 0 (Write advances the file offset, but
+	// for request-response files we need to read the result from the start)
+	var result []byte
+	buf := make([]byte, 8192)
+	for offset := int64(0); ; {
+		n, err := fid.ReadAt(buf, offset)
+		if n > 0 {
+			result = append(result, buf[:n]...)
+			offset += int64(n)
+		}
+		if err == io.EOF || n == 0 {
+			break
+		}
+		if err != nil {
+			return nil, fmt.Errorf("read: %w", err)
+		}
 	}
 
 	return json.RawMessage(result), nil
diff --git a/toolsrv/integration_test.go b/toolsrv/integration_test.go
index 4b543f8..4a248fc 100644
--- a/toolsrv/integration_test.go
+++ b/toolsrv/integration_test.go
@@ -6,10 +6,12 @@ package toolsrv
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 )
@@ -208,6 +210,53 @@ func TestIntegration_BasicOperations(t *testing.T) {
 	t.Logf("ListTools returned %d tools", len(tools))
 }
 
+func TestIntegration_ToolExecution(t *testing.T) {
+	socketPath, cleanup := startTestServer(t)
+	defer cleanup()
+
+	conn, err := Dial(socketPath, "test-secret-exec")
+	if err != nil {
+		t.Fatalf("Dial failed: %v", err)
+	}
+	defer conn.Close()
+
+	// Load the shell tool
+	if err := conn.LoadTool("shell"); err != nil {
+		t.Fatalf("LoadTool failed: %v", err)
+	}
+
+	// Verify it's loaded
+	tools, err := conn.ListTools()
+	if err != nil {
+		t.Fatalf("ListTools failed: %v", err)
+	}
+	found := false
+	for _, tool := range tools {
+		if tool.Name == "shell" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("shell tool not found after loading")
+	}
+
+	// Execute a tool
+	ctx := context.Background()
+	args := json.RawMessage(`{"cmd": "echo hello from test"}`)
+	result, err := conn.CallTool(ctx, "shell", args)
+	if err != nil {
+		t.Fatalf("CallTool failed: %v", err)
+	}
+
+	// Result should be JSON containing the output
+	resultStr := string(result)
+	if !strings.Contains(resultStr, "hello from test") {
+		t.Errorf("unexpected result: %s", resultStr)
+	}
+	t.Logf("Tool result: %s", resultStr)
+}
+
 func TestIntegration_ProcessKeeperReconnect(t *testing.T) {
 	socketPath, cleanup := startTestServer(t)
 	defer cleanup()