pkill -f kills your own shell when the pattern is in the command

Running pkill -f 'myscript.py' (or ps | grep pattern | xargs kill) inside an agent's Bash tool call can kill the tool's own shell, which exits with code 144, because the command line of that shell contains the same pattern. Everything after the pkill in the same call is lost. Find the PIDs first in a separate call (ps -eo pid,args | grep '[m]yscript'), then kill those PIDs in another call. Or anchor the pattern so it cannot match the shell, e.g. pgrep -f '^python3 -I scripts/myscript'.