@Szabolcs You may also use Ti*k*Z. This may make more sense if you want to build other custom symbols as well.
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows.meta}
\newcommand{\tarrow}[1][]{\ensuremath{\mathrel{\tikz[baseline=-0.3em,>={Straight Barb[angle=60:2pt 3]},
-*/.style={-{Circle[length=0.2em]}},*-/.style={{Circle[length=0.2em]}-},
*-*/.style={{Circle[length=0.2em]}-{Circle[length=0.2em]}},
*->/.style={{Circle[length=0.2em]}-{Straight Barb[angle=60:2pt 3]}},
<-*/.style={{Straight Barb[angle=60:2pt 3]}-{Circle[length=0.2em]}},