Question: For some reason I feel its overkilling on the use of article(the) here, 

> 
> To refine the results, please use the categories on the left
> 
> 
> 

Can someone help?

Answer: 
In my opinion, the phrases: 

1. 'the results' - refers to the specific results that will be refined;
2. 'the categories', - refers to the specific (provided) categories; and,
3. 'the left' - refers to the specific side (i.e., not the right side, not the top, etc.).

So, I don't think the word 'the' is overused.
Being strict, it depends on context.

If this message is an instruction provided before any results have been presented, then "the results" doesn't quite make sense because "the" is the *definite article*. That means "the results" refers to a specific set of results. Which specific results? If results don't already exist, it's not clear. I'll likely assume you're talking about "the results [of the next search]". I'd be right, so you'd still be communicating successfully, but it's not ideal.

On the other hand, if the message doesn't appear until after a search is performed and some results (especially a large number of them) are presented, it would work perfectly because "the results" refers to a specific set of results that exist in context.