Here are some attributes of giving feedback in a highly constructive way that we have learned and used over the years.
Ideally feedback, positive or negative, is given as close to the event as possible. Regular 1:1 meetings are a great venue for delivering feedback.
Gather evidence for the feedback instead of relying on vague reports or hunches. Have concrete examples, ideally more than one for negative feedback.
Describe behaviors (is late to meetings) rather than traits or emotions (doesn't care about coworkers). You'll never know anyone else's thoughts, feelings, or motivations. You can observe behaviors in an objective and factual manner. This can be a hard habit change if you've built up years of giving feedback in the other way, but keep at it, it is worth switching.
When you describe a behavior, also say the result. This goes for positive and negative feedback. "When you review pull requests right away, you really help the velocity of the whole team." "When you are regularly late for meetings, the effectiveness of the rest of the meeting is reduced because the meeting leader has to repeat information or wait for you."
Don't dwell on the past, but focus on the future. The future can be altered, the past will never change.
Giving constructive feedback to a top performer is not nitpicking, it is actually some of the highest leverage work we can do. Most folks (not everyone of course) are eager to hear ways they can keep growing. We don't help folks by having no ideas for them.
TTS, as a part of GSA, has a mature 18F only, performance management and recognition system. This includes an end-of-year performance assessment.