If those 3 ratings are high, e.g, treadwear 300+, traction AA & temperature A, then it would be a good tyre compared to ones with lesser ratings. Except for treadwear, most tyres have traction A & temperature A rating at the least.

However bear in mind, these figures are put on by the manufacturer themselves as an indication only. These figures are not verified by a third-party organization to confirm whether the figures are correct. I believe big manufacturers like Michelin, Goodyear & Continental's figures can be trusted.