What was The characteristic of polonius that most directly lead to his death?

Polonius's characteristic of being overly curious and meddlesome ultimately led to his death. His inclination to spy on others, particularly his decision to hide behind the arras in Gertrude's chamber, made him vulnerable. This act of eavesdropping not only revealed his lack of discretion but also resulted in him being mistakenly killed by Hamlet, showcasing the dangers of his intrusive behavior.