diff --git a/skills/using-webapp-salesforce-data/scripts/graphql-search.sh b/skills/using-webapp-salesforce-data/scripts/graphql-search.sh
old mode 100644
new mode 100755
index 28f923c..e11f41e
--- a/skills/using-webapp-salesforce-data/scripts/graphql-search.sh
+++ b/skills/using-webapp-salesforce-data/scripts/graphql-search.sh
@@ -1,20 +1,23 @@
 #!/usr/bin/env bash
+set -euo pipefail  # exit on error (-e), undefined vars (-u), and propagate pipeline failures (-o pipefail)
 # graphql-search.sh — Look up one or more Salesforce entities in schema.graphql.
 #
 # Run from the SFDX project root (where schema.graphql lives):
-#   bash .a4drules/skills/using-salesforce-data/graphql-search.sh Account
-#   bash .a4drules/skills/using-salesforce-data/graphql-search.sh Account Contact Opportunity
+#   bash scripts/graphql-search.sh Account
+#   bash scripts/graphql-search.sh Account Contact Opportunity
 #
 # Pass a custom schema path with -s / --schema:
-#   bash .a4drules/skills/using-salesforce-data/graphql-search.sh -s /path/to/schema.graphql Account
-#   bash .a4drules/skills/using-salesforce-data/graphql-search.sh --schema ./other/schema.graphql Account Contact
+#   bash scripts/graphql-search.sh -s /path/to/schema.graphql Account
+#   bash scripts/graphql-search.sh --schema ./other/schema.graphql Account Contact
 #
 # Output sections per entity:
-#   1. Type definition   — all fields and relationships
-#   2. Filter options    — <Entity>_Filter input (for `where:`)
-#   3. Sort options      — <Entity>_OrderBy input (for `orderBy:`)
-#   4. Create input      — <Entity>CreateRepresentation (for create mutations)
-#   5. Update input      — <Entity>UpdateRepresentation (for update mutations)
+#   1. Type definition          — all fields and relationships
+#   2. Filter options           — <Entity>_Filter input (for `where:`)
+#   3. Sort options             — <Entity>_OrderBy input (for `orderBy:`)
+#   4. Create mutation wrapper  — <Entity>CreateInput
+#   5. Create mutation fields   — <Entity>CreateRepresentation (for create mutations)
+#   6. Update mutation wrapper  — <Entity>UpdateInput
+#   7. Update mutation fields   — <Entity>UpdateRepresentation (for update mutations)
 
 SCHEMA="./schema.graphql"
 
@@ -62,6 +65,19 @@ if [ ! -f "$SCHEMA" ]; then
   exit 1
 fi
 
+if [ ! -r "$SCHEMA" ]; then
+  echo "ERROR: schema.graphql is not readable at $SCHEMA"
+  echo "  Check file permissions: ls -la $SCHEMA"
+  exit 1
+fi
+
+if [ ! -s "$SCHEMA" ]; then
+  echo "ERROR: schema.graphql is empty at $SCHEMA"
+  echo "  Regenerate it from the webapp dir:"
+  echo "    cd force-app/main/default/webapplications/<app-name> && npm run graphql:schema"
+  exit 1
+fi
+
 # ── Helper: extract lines from a grep match through the closing brace ────────
 # Prints up to MAX_LINES lines after (and including) the first match of PATTERN.
 # Uses a generous line count — blocks are always closed by a "}" line.
@@ -72,68 +88,104 @@ extract_block() {
   local max_lines="$3"
 
   local match
-  match=$(grep -nE "$pattern" "$SCHEMA" | head -1)
+  local grep_exit=0
+  match=$(grep -nE "$pattern" "$SCHEMA" | head -1) || grep_exit=$?
+
+  if [ "$grep_exit" -eq 2 ]; then
+    echo "  ERROR: grep failed on pattern: $pattern" >&2
+    return 1
+  fi
 
   if [ -z "$match" ]; then
     echo "  (not found: $pattern)"
-    return
+    return 3
   fi
 
   echo "### $label"
   grep -E "$pattern" "$SCHEMA" -A "$max_lines" | \
     awk '/^\}$/{print; exit} {print}' | \
-    head -n "$max_lines"
+    head -n "$max_lines" || true
   echo ""
 }
 
 # ── Main loop ────────────────────────────────────────────────────────────────
 
 for ENTITY in "$@"; do
+  # Validate entity name: must be a valid PascalCase identifier (letters, digits, underscores)
+  if [[ ! "$ENTITY" =~ ^[A-Za-z_][A-Za-z0-9_]*$ ]]; then
+    echo "ERROR: Invalid entity name: '$ENTITY'"
+    echo "  Entity names must start with a letter or underscore, followed by letters, digits, or underscores."
+    echo "  Examples: Account, My_Custom_Object__c"
+    continue
+  fi
+
   echo ""
   echo "======================================================================"
   echo "  SCHEMA LOOKUP: $ENTITY"
   echo "======================================================================"
   echo ""
 
+  found=0
+
+  # Helper: call extract_block, track matches, surface errors
+  try_extract() {
+    local rc=0
+    extract_block "$@" || rc=$?
+    if [ "$rc" -eq 0 ]; then
+      found=$((found + 1))
+    elif [ "$rc" -eq 1 ]; then
+      echo "  Aborting lookup for '$ENTITY' due to grep error" >&2
+    fi
+    # rc=3 is not-found — continue silently (already printed by extract_block)
+  }
+
   # 1. Type definition — all fields and relationships
-  extract_block \
+  try_extract \
     "Type definition — fields and relationships" \
     "^type ${ENTITY} implements Record" \
     200
 
   # 2. Filter input — used in `where:` arguments
-  extract_block \
+  try_extract \
     "Filter options — use in where: { ... }" \
     "^input ${ENTITY}_Filter" \
     100
 
   # 3. OrderBy input — used in `orderBy:` arguments
-  extract_block \
+  try_extract \
     "Sort options — use in orderBy: { ... }" \
     "^input ${ENTITY}_OrderBy" \
     60
 
-  # 4. Create mutation inputs
-  extract_block \
+  # 4. Create mutation wrapper
+  try_extract \
     "Create mutation wrapper — ${ENTITY}CreateInput" \
     "^input ${ENTITY}CreateInput" \
     10
 
-  extract_block \
+  # 5. Create mutation fields
+  try_extract \
     "Create mutation fields — ${ENTITY}CreateRepresentation" \
     "^input ${ENTITY}CreateRepresentation" \
     100
 
-  # 5. Update mutation inputs
-  extract_block \
+  # 6. Update mutation wrapper
+  try_extract \
     "Update mutation wrapper — ${ENTITY}UpdateInput" \
     "^input ${ENTITY}UpdateInput" \
     10
 
-  extract_block \
+  # 7. Update mutation fields
+  try_extract \
     "Update mutation fields — ${ENTITY}UpdateRepresentation" \
     "^input ${ENTITY}UpdateRepresentation" \
     100
 
+  if [ "$found" -eq 0 ]; then
+    echo "WARNING: No schema entries found for '$ENTITY'."
+    echo "  - Names are PascalCase (e.g., 'Account' not 'account')"
+    echo "  - Custom objects may need deployment first"
+  fi
+
   echo ""
 done