I reported chasing dog with no lead - what a sight! (5,3)
I believe the answer is:
eagle eye
'what a sight' is the definition.
(I have seen 'Keen sight' mean 'eagle eye' so perhaps 'sight' could also mean 'eagle eye')
'i reported chasing dog with' is the wordplay.
'reported' indicates a 'sounds like' (homophone) clue.
'chasing' is a charade indicator (letters next to each other) (some letters chase after others).
'dog with' becomes 'eagle' (I am not sure about this - if you are sure you should believe this answer much more).
'i' sounds like 'eye'.
'eye' put after 'eagle' is 'EAGLE-EYE'.
'no lead' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for eagle eye that I've seen before include "Keen sight" , "Ability to observe fine detail" , "one envisages a long way off" , "Critical inspection" , "Keenness of vision" .)