Actually I have understood that there is no need for any customization.
If I search  within main page of node then there is no description  field there.
But if I search whithin document library, there is a description field!
So this is what I need.
Also I have found that it has two different algorithms for searching and It
returns different search results.

Your subject line "SharePoint Services" conflicts with your text "SharePoint
Team Services" as these are two different products.

I suspect that your subject line is right and that you are using the 2003
product Windows sharepoint  Services (free download; runs only on Win 2003
Servers) and not the 2001 product SharePoint Team services  (came with FP
2002 CDs and Office XP with FP 2002 CDs).

This is the newsgroup for the CAML language as used with SharePoint Team
Services. You aren't using CAML and you probably aren't using STS.

Programming questions for WSS (which this probably is) go to

microsoft.public.sharepoint.windowsservices.development

while non-Programming questions for WSS go to

microsoft.public.sharepoint.windowsservices

I am sorry for posting in wrong place.
Yes, I am using Windows SharePoint Services.

No problem. Microsoft don't make it easy to find the WSS newsgroups.

My text was rubbish. It should have been your question  isn't a CAML
question. Both WSS and STS *use* CAML.