Is GSC data (branded clicks + impressions) a good indicator for how well your PR activity has performed for the year?

[Jacksons_Fencing]

We are reviewing our creative / PR agency and are intending to use our GSC data as a way to assess their performance...

[Martijn_Scheijbeler]

I would definitely use it as some of the metrics as long as the traffic is coming to certain pages that might have been pushed by the PR agency. Another metric that would be good to look at is the number of new links/domains that are linking with the anchor text that is your company name. I would expect most PR agencies to focus on company names.