I'm having success with simple YAML schema. One thing that's very helpful for the prompt is to include "description" and "example":

      -
         column name: salary_max
         format: number
         example: 150,000
         description: Salary Maximum
      -
         column name: keywords
         format: string
         example: engineer, python, docker, remote
         description: Relevant Keywords (Comma separated keywords used for filtering and matching jobs to candidates)