parallel optimization groundwork

pkg/tools/mcp.go

@@ -346,13 +346,30 @@ type mcpClient struct {
 	cmd        *exec.Cmd
 	stdin      io.WriteCloser
 	reader     *bufio.Reader
-	stderr     bytes.Buffer
+	stderr     mcpSafeBuffer
 
 	writeMu sync.Mutex
 	waiters sync.Map
 	nextID  atomic.Int64
 }
 
+type mcpSafeBuffer struct {
+	mu  sync.Mutex
+	buf bytes.Buffer
+}
+
+func (b *mcpSafeBuffer) Write(p []byte) (int, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.buf.Write(p)
+}
+
+func (b *mcpSafeBuffer) String() string {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.buf.String()
+}
+
 type mcpInbound struct {
 	JSONRPC string                 `json:"jsonrpc"`
 	ID      interface{}            `json:"id,omitempty"`