10 Characteristcs of   a good tester is :

1) Critical Thinker
2) Should be diplomatic enough to handle Developers, in 
order to maintain Team spirit.
3) Domain Knowledge should be most important.
4) Well versed in communation and should be expressive .
5) knowledge of Language platform would be an added 
advantage.
6) Must be aware of QMS ( Quality Managemant system)
----------
thats all what hits in my mind.

A good tester is a one who could work on an appln under any 
circumstances and make the appln fail.

1) Having project knowledge 
2) pointing out hidden bugs 
3) Domain knowledge
4) hands on exp on various testing methods
5) should always Question every scenario in 2 ways (WHY,How)
6) Verifying
7) Validating
8) Quality
9)

HI Anamica,

Ur answer is good, but if u cover some more points it could 
be more better.

1. A tester need to provide the confidance in the system.
2. Tester should have test to break attitude.