diff --git a/list-linuxcnc-source-manifest-sources.sh b/list-linuxcnc-source-manifest-sources.sh
index f5118d5..ac0d778 100755
--- a/list-linuxcnc-source-manifest-sources.sh
+++ b/list-linuxcnc-source-manifest-sources.sh
@@ -3,6 +3,9 @@ set -euo pipefail
 
 cd "$(dirname "$0")"
 
+# LinuxCNC source basis: linuxcnc-rs274-source-files.txt enumerates the native
+# RS274 interpreter, Python binding, tooldata, support-object, and metadata
+# inputs that are linked by the LinuxCNC source-backed native test path.
 manifest=${1:-linuxcnc-rs274-source-files.txt}
 filter_group=${2:-core}
 output_mode=${3:-relative}
diff --git a/list-linuxcnc-source-support-objects.sh b/list-linuxcnc-source-support-objects.sh
index 38dfef7..654c111 100755
--- a/list-linuxcnc-source-support-objects.sh
+++ b/list-linuxcnc-source-support-objects.sh
@@ -3,6 +3,9 @@ set -euo pipefail
 
 cd "$(dirname "$0")"
 
+# LinuxCNC source basis: native source-link support objects come from the
+# LinuxCNC-built RS274 Python bindings and support sources listed in
+# linuxcnc-rs274-source-files.txt, including emcops, dummyemcstat, and stat_msg.
 linuxcnc_root=${LINUXCNC_ROOT:-../linuxcnc}
 filter=${1:-}
 preflight_cache_dir=${CNC_SIM_PREFLIGHT_CACHE_DIR:-build/linuxcnc-helper-preflight-cache}
diff --git a/test-linuxcnc-source-objects.sh b/test-linuxcnc-source-objects.sh
index 5051438..5440b57 100755
--- a/test-linuxcnc-source-objects.sh
+++ b/test-linuxcnc-source-objects.sh
@@ -3,6 +3,9 @@ set -euo pipefail
 
 cd "$(dirname "$0")"
 
+# LinuxCNC source basis: this probe compiles the core RS274 interpreter sources
+# selected from linuxcnc-rs274-source-files.txt, keeping the native source
+# object set tied to LinuxCNC src/emc/rs274ngc and tooldata source entries.
 linuxcnc_root=${LINUXCNC_ROOT:-../linuxcnc}
 cxx=${CXX:-g++}
 if [[ -z ${CXX:-} ]] && command -v ccache >/dev/null 2>&1; then
diff --git a/test-linuxcnc-source-syntax.sh b/test-linuxcnc-source-syntax.sh
index f7a5d2e..8c4e9e8 100755
--- a/test-linuxcnc-source-syntax.sh
+++ b/test-linuxcnc-source-syntax.sh
@@ -3,6 +3,9 @@ set -euo pipefail
 
 cd "$(dirname "$0")"
 
+# LinuxCNC source basis: this syntax probe checks the native RS274 manifest's
+# core, binding, and tooldata entries from LinuxCNC src/emc/rs274ngc and
+# src/emc/tooldata before source-object and source-link tests consume them.
 linuxcnc_root=${LINUXCNC_ROOT:-../linuxcnc}
 cxx=${CXX:-g++}
 if [[ -z ${CXX:-} ]] && command -v ccache >/dev/null 2>&1; then
diff --git a/test-native.sh b/test-native.sh
index 3bb88b7..f0668e1 100755
--- a/test-native.sh
+++ b/test-native.sh
@@ -54,6 +54,10 @@ grep -F 'metadata:src/emc/tooldata/tooldata_nml.cc:source basis for wasm-safe to
 grep -F 'LinuxCNC source basis: this probe derives required Python C API exports from' test-linuxcnc-wasm-python-c-api-symbols.sh >/dev/null
 grep -F 'LinuxCNC source basis: this probe compares wasm-safe tooldata runtime stubs' test-linuxcnc-wasm-tooldata-runtime-symbols.sh >/dev/null
 grep -F 'LinuxCNC source basis: the standalone probe links src/emc/rs274ngc/interp_base.cc' test-linuxcnc-wasm-interp-base-link.sh >/dev/null
+grep -F 'LinuxCNC source basis: linuxcnc-rs274-source-files.txt enumerates the native' list-linuxcnc-source-manifest-sources.sh >/dev/null
+grep -F 'LinuxCNC source basis: native source-link support objects come from the' list-linuxcnc-source-support-objects.sh >/dev/null
+grep -F 'LinuxCNC source basis: this probe compiles the core RS274 interpreter sources' test-linuxcnc-source-objects.sh >/dev/null
+grep -F 'LinuxCNC source basis: this syntax probe checks the native RS274 manifest' test-linuxcnc-source-syntax.sh >/dev/null
 grep -F 'header:src/emc/ini/inifile.h:LinuxCNC C INI reader declarations exported by ini Submakefile' linuxcnc-rs274-wasm-source-files.txt >/dev/null
 grep -F 'header:src/emc/ini/inifile.hh:LinuxCNC C++ INI reader declarations used by inifile.cc' linuxcnc-rs274-wasm-source-files.txt >/dev/null
 grep -F 'metadata:src/emc/ini/Submakefile:LinuxCNC ini build metadata defining liblinuxcncini source and exported headers' linuxcnc-rs274-wasm-source-files.txt >/dev/null