diff --git a/neuralnetworks/1.0/IPreparedModel.hal b/neuralnetworks/1.0/IPreparedModel.hal
index 5320050..3dc3202 100644
--- a/neuralnetworks/1.0/IPreparedModel.hal
+++ b/neuralnetworks/1.0/IPreparedModel.hal
@@ -49,11 +49,14 @@
      * must not change the content of any of the data objects corresponding to
      * 'request' inputs.
      *
-     * If the prepared model was prepared from a model wherein all
-     * tensor operands have fully specified dimensions, and the inputs
-     * to the function are valid, then the execution should launch
-     * and complete successfully (ErrorStatus::NONE). There must be
-     * no failure unless the device itself is in a bad state.
+     * If the prepared model was prepared from a model wherein all tensor
+     * operands have fully specified dimensions, and the inputs to the function
+     * are valid, then:
+     * - the execution should launch successfully (ErrorStatus::NONE): There
+     *   must be no failure unless the device itself is in a bad state.
+     * - if at execution time every operation's input operands have legal
+     *   values, the execution should complete successfully (ErrorStatus::NONE):
+     *   There must be no failure unless the device itself is in a bad state.
      *
      * Multiple threads can call the execute function on the same IPreparedModel
      * object concurrently with different requests.