diff --git a/packaging/mother/MOTHER-SETUP.md b/packaging/mother/MOTHER-SETUP.md
index e2bc9c4..630a4a4 100644
--- a/packaging/mother/MOTHER-SETUP.md
+++ b/packaging/mother/MOTHER-SETUP.md
@@ -20,9 +20,10 @@ infrastructure.
 
 ## Prerequisites
 
-- **`python3` on PATH** — `geodesic-dome-mcp` is a python3 script (standard
-  library only, no `pip install`). `setup-mother.sh` preflights this and aborts
-  if it is missing. Install with `pkg install python3`.
+- **`python3` with `numpy` + `Pillow`** — `geodesic-dome-mcp` imports both at
+  module load (not stdlib-only). `setup-mother.sh` preflights that python3 exists
+  *and* that `numpy`/`PIL` actually import, aborting if either is missing. Install
+  with `pkg install python3 py311-numpy py311-pillow`.
 - **`COLIBRI_AUTOSPAWN_RPC_PROMPT` (a decision, not a dependency)** — the daemon
   reads this on boot (`crates/colibri-daemon/src/socket.rs`). Set it to have the
   daemon auto-spawn an agent with that opening prompt on boot; leave it unset for
diff --git a/packaging/mother/setup-mother.sh b/packaging/mother/setup-mother.sh
index 98c8c34..05f427c 100755
--- a/packaging/mother/setup-mother.sh
+++ b/packaging/mother/setup-mother.sh
@@ -74,7 +74,16 @@ if ! command -v python3 >/dev/null 2>&1; then
     echo "         Install it first:  pkg install python3"
     exit 1
 fi
-echo "  python3: $(command -v python3) OK"
+# geodesic-dome-mcp imports numpy + PIL at module load, so a present python3
+# is not enough — verify the modules actually import, or the tool fails only
+# when the MCP host first calls it.
+if ! python3 -c "import numpy, PIL" >/dev/null 2>&1; then
+    echo "  ERROR: python3 present but numpy/Pillow are not importable."
+    echo "         geodesic-dome-mcp needs both (imported at module load)."
+    echo "         Install them:  pkg install py311-numpy py311-pillow"
+    exit 1
+fi
+echo "  python3: $(command -v python3) (numpy + PIL OK)"
 echo ""
 
 # ── 1. colibri binaries ───────────────────────────────────────────────