diff --git a/ui-modules/blueprint-composer/app/components/providers/blueprint-service.provider.js b/ui-modules/blueprint-composer/app/components/providers/blueprint-service.provider.js
index ecfefae..38687da 100644
--- a/ui-modules/blueprint-composer/app/components/providers/blueprint-service.provider.js
+++ b/ui-modules/blueprint-composer/app/components/providers/blueprint-service.provider.js
@@ -530,10 +530,7 @@
     function addParameterDefinition(params, key) {
         params.push({
             "name": key,
-            "description": "",
             "type": "string",
-            "default": "",
-            "constraints": [],
         });
     }
 
diff --git a/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.directive.js b/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.directive.js
index dae9220..052bf18 100644
--- a/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.directive.js
+++ b/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.directive.js
@@ -391,6 +391,7 @@
                 item: $item,
                 newName: $item.name,
                 constraints: $item.constraints ? JSON.stringify($item.constraints) : '',
+                original: Object.assign({}, $item),
                 json: JSON.stringify($item, null, "  "),
             };
         };
@@ -1109,11 +1110,35 @@
                     }
                      
                     try {
-                        item.constraints = JSON.parse(scope.state.parameters.edit.constraints);
+                        let c = scope.state.parameters.edit.constraints ? JSON.parse(scope.state.parameters.edit.constraints) : [];
+                        if (Array.isArray(c)) {
+                            if (c.length==0) { 
+                                delete item['constraints'];
+                            } else {
+                                item.constraints = c;
+                            }
+                        } else {
+                            scope.state.parameters.edit.errors.push({ message: "Constraint JSON must be a list" });
+                        }
                     } catch (e) {
                         // $log.warn("ERROR parsing constraints", scope.state.parameters.edit.constraints, e);
                         scope.state.parameters.edit.errors.push({ message: "Invalid constraint JSON" });
                     }
+                    
+                    // empty values are removed
+                    if (item.description == '') {
+                        delete item['description'];
+                    } 
+                    if (item.label == '') {
+                        delete item['label'];
+                    } 
+                    if (item.default == '') {
+                        if (scope.state.parameters.edit.original.default!=='') {
+                            // don't delete if default was explicitly set in yaml as "";
+                            // this allows empty string defaults to be used (although you can't set them in the visual ui)
+                            delete item['default'];
+                        }
+                    }
                 }
             }
             
diff --git a/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.template.html b/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.template.html
index 1f21e08..0b28abd 100644
--- a/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.template.html
+++ b/ui-modules/blueprint-composer/app/components/spec-editor/spec-editor.template.html
@@ -136,7 +136,9 @@
                           <div class="input-group hide-when-collapsed" ng-if="state.parameters.codeModeActive[item.name]">
                             <span class="main-control span-for-rounded-edge">
                                 <textarea ng-model="state.parameters.edit.json" class="form-control rounded-edge" name="{{item.name}}" id="json-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="(required)" 
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel"></textarea>
                             </span>
                           </div>
@@ -145,7 +147,9 @@
                             <div class="param-field"> <span class="param-field-label">Key</span> 
                                 <span class="param-field-value">
                                     <textarea ng-model="state.parameters.edit.newName" class="form-control rounded-edge" id="name-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="(required)" 
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel">
                                     </textarea>
                                 </span>
@@ -153,7 +157,9 @@
                             <div class="param-field"> <span class="param-field-label">Type</span> 
                                 <span class="param-field-value">
                                     <textarea ng-model="filteredParams[$index].type" class="form-control rounded-edge" id="type-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="(required)" 
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel">
                                     </textarea>
                                 </span>
@@ -161,7 +167,9 @@
                             <div class="param-field"> <span class="param-field-label">Default value</span> 
                                 <span class="param-field-value">
                                     <textarea ng-model="filteredParams[$index].default" class="form-control rounded-edge" id="default-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="{{ state.parameters.edit.original.default == '' ? '(empty)' : '(not set)' }}" 
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel">
                                     </textarea>
                                 </span>
@@ -169,7 +177,9 @@
                             <div class="param-field"> <span class="param-field-label">Display name</span> 
                                 <span class="param-field-value">
                                     <textarea ng-model="filteredParams[$index].label" class="form-control rounded-edge" id="label-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="(not set)" 
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel">
                                     </textarea>
                                 </span>
@@ -177,20 +187,24 @@
                             <div class="param-field"> <span class="param-field-label">Description</span> 
                                 <span class="param-field-value">
                                     <textarea ng-model="filteredParams[$index].description" class="form-control rounded-edge" id="description-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="(not set)" 
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel">
                                     </textarea>
                                 </span>
                             </div>
                             <div class="param-field"> <span class="param-field-label">Constraints
                                     <i class="fa fa-fw fa-info-circle" popover-trigger="'mouseenter'"
-                                           uib-popover="Constraints such as required or forbiddenUnless(otherKey), expressed as a JSON list (wrapped in brackets)"
+                                           uib-popover="Constraints such as &quot;required&quot; or &quot;forbiddenUnless(otherKey)&quot;, expressed as a JSON list (wrapped in square brackets)"
                                            x-popover-class="spec-editor-popover" 
                                            popover-placement="top-left" popover-append-to-body="true"></i>
                                 </span> 
                                 <span class="param-field-value">
                                     <textarea ng-model="state.parameters.edit.constraints" class="form-control rounded-edge code" id="constraints-{{item.name}}"
-                                          auto-grow placeholder="(empty)" ng-focus="specEditor.recordParameterFocus(item)"
+                                          auto-grow 
+                                          placeholder="(none)"
+                                          ng-focus="specEditor.recordParameterFocus(item)"
                                           on-enter="specEditor.advanceOutToFormGroupInPanel">
                                     </textarea>
                                 </span>