Reasons to Mark a Manuscript

Yep, I'm guilty. I just made critique comments for my fabulous new critique group and found myself inserting a few suggestions of another way I would have worded a phrase or sentence. This got me thinking about how often we change another person's words. Sometimes critiquers slip their preferences into the story. Ideas just pop into our heads. If a phrase here or there doesn't feel right, we often want to put our own word choice in. Is it an improvement? Hard to say. I ask myself why I like it better?
TIP: If you can't name a reason, leave it alone. A few specific suggestions can show/teach, but 90% of your markings/comments should suggest reasons rather than making the actual fix.

The pen is a mighty instrument. Be wise.

REASONS: 
Add clarity, emotion, tension, description, or information. Replace weak verbs, unnatural dialogue, setting or character inconsistencies. Delete filler words and redundancy. Reword awkward phrases and sentence structure that doesn't vary, pacing that is too fast or slow. You can probably think of more.

Depending on the writer's skill level, you might need to teach with an EXAMPLE. Someone new to critiquing might not 'get it' when a marking says, "Tighten here." You might leave an example and add the reason.
Original: One of us is going to have to go home. Change: One of us needs to go home.
Reasons: Eliminates filler words and the weak To Be verb, same message.

DO mark those extra nice passages with smiley faces, stars, or words. We like to see positive markings too. Interestingly, the reasons you like them are the correct implementation of the reasons above. You might mark, "Good clarification" or "Nice description". Some writers need more positive feedback than others. Be kind. Hopefully we get to the point of understanding that a marked up manuscript means someone took the time to be helpful--if they know their reasons, that is.

Have you had a good or bad critique experience? Did their comments include reasons?
Keep writing and have a great week!