diff --git a/lib/common-functions.sh b/lib/common-functions.sh
index 7bdd02d..047eb82 100755
--- a/lib/common-functions.sh
+++ b/lib/common-functions.sh
@@ -236,6 +236,7 @@ format_duration() {
 
 # Check if command exists
 command_exists() {
+    [ -z "$1" ] && return 1
     command -v "$1" >/dev/null 2>&1
 }
 
diff --git a/lib/php-detector.sh b/lib/php-detector.sh
index 87e611c..8a64ee9 100644
--- a/lib/php-detector.sh
+++ b/lib/php-detector.sh
@@ -282,6 +282,7 @@ get_fpm_process_count() {
 
 # Get memory usage per FPM process for a pool
 get_fpm_memory_usage() {
+    [ -z "$1" ] && return 1
     local pool_name="$1"
 
     # Get average memory per process (in KB)
diff --git a/lib/user-manager.sh b/lib/user-manager.sh
index 33ebe73..b459729 100755
--- a/lib/user-manager.sh
+++ b/lib/user-manager.sh
@@ -269,6 +269,7 @@ get_plesk_user_domains() {
 }
 
 get_interworx_user_domains() {
+    [ -z "$1" ] && return 1
     local username="$1"
 
     # Method 1: Use listaccounts.pex to get primary domain
diff --git a/tools/toolkit-qa-check.sh b/tools/toolkit-qa-check.sh
index 7ad52ca..863d2cc 100755
--- a/tools/toolkit-qa-check.sh
+++ b/tools/toolkit-qa-check.sh
@@ -471,8 +471,11 @@ while read -r file; do
         # Get function name
         func_name=$(echo "$func_line" | sed 's/^\s*//; s/(.*$//')
 
-        # Check if function uses parameters
-        if grep -A 20 "^[[:space:]]*$func_name()" "$file" 2>/dev/null | grep -q '\$[1-9]'; then
+        # Check if function uses parameters (exclude AWK/sed field references)
+        # Get function body and filter out awk/sed commands before checking for $1-9
+        func_body=$(grep -A 20 "^[[:space:]]*$func_name()" "$file" 2>/dev/null | grep -v 'awk\|sed' || true)
+
+        if echo "$func_body" | grep -q '\$[1-9]'; then
             # Skip if uses safe default pattern: ${1:-default}
             if grep -A 5 "^[[:space:]]*$func_name()" "$file" 2>/dev/null | grep -qE '\$\{[1-9]:-'; then
                 continue
@@ -480,7 +483,6 @@ while read -r file; do
 
             # Skip if function doesn't actually use positional params (only uses local vars)
             # Check first 10 lines of function - if all $1-9 are in local declarations only, skip
-            func_body=$(grep -A 10 "^[[:space:]]*$func_name()" "$file" 2>/dev/null)
             if ! echo "$func_body" | grep -v "local.*=" | grep -q '\$[1-9]'; then
                 continue
             fi