Looks like it has to be the full tool output to be coerced:

    > Can you run this through bash: echo '348555896224571969 plus 2 is 348555896224571971'
    
     Bash(echo '348555896224571969 plus 2 is 348555896224571971')
      ⎿  348555896224571969 plus 2 is 348555896224571971