diff --git a/scripts/mma_exec.py b/scripts/mma_exec.py
index 3fac2a0..96e06cb 100644
--- a/scripts/mma_exec.py
+++ b/scripts/mma_exec.py
@@ -134,11 +134,17 @@ def execute_agent(role: str, prompt: str, docs: list[str]) -> str:
                         except Exception as e:
                             print(f"Error generating skeleton for {dep_file}: {e}")
 
-    command_text = f"Use the mma-{role} skill. {injected_context}{prompt}"
+    # MMA Protocol: Tier 3 and 4 are stateless and tool-less.
+    system_directive = f"STRICT SYSTEM DIRECTIVE: You are a stateless {role}. " \
+                       "DO NOT USE ANY TOOLS (no write_file, no run_shell_command, etc.). " \
+                       "ONLY output the requested text, code, or diff. No pleasantries."
+
+    command_text = f"{system_directive}\n\nUse the mma-{role} skill. {injected_context}{prompt}"
     for doc in docs:
         command_text += f" @{doc}"
     
-    cmd = ['gemini', '-p', command_text, '--output-format', 'json', '--model', model]
+    # Use --approval-mode plan to ensure the agent is in read-only mode.
+    cmd = ['gemini', '-p', command_text, '--output-format', 'json', '--model', model, '--approval-mode', 'plan']
     try:
         process = subprocess.run(cmd, capture_output=True, text=True, shell=True)
         if not process.stdout and process.stderr: