Master Smith

You study the art of crafting weapons and armor, gaining the following benefits. 

• Increase your strength or constitution by 1 to a maximum of 20.
• You gain proficiency with smiths tools and leather workers tools. If you are already proficient in the skill, you add double the proficiency bonus to skill checks made with those tools.
• During a short or long rest, you can mend, tighten, modify, and improve one allies armor giving them a +1 to AC until the next long rest.