SOME INSTRUCTIONS TO DESCRIBE TOOLS IN:

http://www.eslgold.com/writing/description_object.html 

How to Write a Description of an Object

Notes

Vocabulary

Parts Materials Properties Functions

(What are they?) (What is it made of?) (What characteristics/qualities does it have?) (Why are these qualities important?) (uses)

What can it do (by itself) (i.e. it can store records or it stores records)
What can you do with it (i.e. you can lock it or it can be locked [by you])

Purpose

Why are you writing this?
to sell something
to entertain
to inform

Audience

Whom are you writing to?

friends coworkers

children educated people

the general public