Tips & Tricks: Was my chat log ACTUALLY toxic?

For starters, if your chat logs are consistently lengthy, but neither banter nor constructive, that should be a pretty blatant red flag. In-game chat is meant to foster in-game relationships and encourage teamwork. If you're using it to tilt, bash, or otherwise offend or insult another player, you're PROBABLY doing it wrong.

Jungler fails a gank? It. Happens. Your boosted ADC goes 0/5 at 7 minutes? Unlucky. You, however, have the choice of moving on from that game not having said a negative thing and keeping your account in good standing; or you could harrass someone having a bad game, which decreases your team's morale and subsequently your chances of winning, and you can have your account flagged for review/punishment.

With this short trick, you, too, can make sure you don't have to come to PB&M asking whether your reform card shows toxicity:

Keep comments constructive, positive, or at least neutral. In most games, however, you should be focusing on playing the game, which means you'll want to cut down on the time you spend coming up with clever putdowns and insults.

Here's an example: https://boards.na.leagueoflegends.com/en/c/player-behavior-moderation/tWzQalPA-can-someone-tell-me-the-parts-where-i-was-toxic