The Soviet tattletale is not generally spy ship, more often it was DD or FF, just sometimes LST or survey vessel, when warships were in short supply. There was a special duty: KNS or "direct contact ship", the most reliable source of target information for attack forces, combined air, surface and subsurface ones, and this duty could have been assigned to a spy ships very seldom. Spy ships were at sea on their own plans and when they wandered along the CBG it usually meant they have special task to gather more info about some carrier innovation, but they weren't the targeting source. Not too much changed: Russian FFG Admiral Essen was a KNS/tattletale a couple of years ago off Syria tracking the FNS Charles De Gaulle. Nowadays it is quite easier since the satellite links allows to feed the staffs with targeting info constantly. Back in 80s, only a few of Soviet ships had satellite comms equal to USN OE-82 and the main channel to send the info about carrier position, status and evolutions was so-called superfast telegraph, encrypted short messages of 240 letters/digits each, about 1.4 seconds in the air. Enough to inform the staff ashore but far from enough to describe the beauty og summer ocean. And even these messages were vulnerable to USN ECM measures. Sometimes it was natural gambling to find which USN platform is responsible for that fast jamming. Was it S-3 aloft? Some escorting DDG? Carrier herself? When the analysts went crazy unable to determine that platform, KNS would have been paired with the spy ship, whose main task was to resonve that intricate question. This way.