What Ron R said is true.
Any time you measure parts, the data you collect include a bit of imprecision due to measurement variation. If your measurement system does not have adequate repeatability, you can’t be sure of what you are seeing in your process.
Using a designed experiment and assuming the parts themselves do not change between measurements, it is possible to statistically decompose the total observed variation into component portions. It is common in a Gage Repeatability & Reproducibility study (GR&R) to summarize what percent of the total observed variation is attributed to the parts, the operators and the (measurement) equipment. By consensus, the appraisal percentage (the repeatability of the “gage” and the reproducibility of the operators) should be less than 30% of the total. Your supplier is in that range.
When your measuring device is used for inspection, sometimes measurement variation is quantified relative to the total tolerance rather than process variation from the study.
When you wrote the supplier’s report shows “tolerance less than 10%”, I think you meant to say the portion which is measurement variability is <10% of the total tolerance. That would be a great result.