And some UK recruiters play very dirty. They post fake CVs and fake job ads to mine the market. They pose as candidates to get info from other agents; and ask real candidates what other jobs they have applied for.
All I'm asking is basic things like "what tech are they ussing" or "what type of role is it" etc.
Of all my theories for why they can't say up front I'm now leaning towards this one: they need to gather my info so that if the 5-10 minute phone call is fruitless, they'll have enough candidate info on ME to be able to pay for that call, when they say that info in bulk. If they gave away the big parameters first (location, pay range, tech, ..) they know that's when most conversations will end. I haven't tried, but I'm guessing that if I just tell them enough about me first, they'll eventually allow the call to contain details about the position. At that point I'll just say "no thanks, I can't move to city Y", but they are happy they got some good info.