At East Mids the clearance is rarely (if ever) confusing. Particularly with regards to entering the zone - if they can't offer you a clearance straight away they usually tell you that you're not yet cleared. It typically goes like this:
"G-ABCD is at Markfield, request re-join"
"G-CD route towards the southern zone boundary, runway 27, QNH 1013, QFE 1003, you're not yet cleared to enter the zone"
"G-CD wilco, 27, QNH 1013, QFE 1003, not yet cleared into the zone."
"G-CD is cleared for a Sierra Echo arrival not above 2000ft VFR, report the southern zone boundary"
"G-CD cleared Sierra Echo not above 2000ft, wilco."
"G-CD zone in Shepshed" <Shepshed is the town on the zone boundary>
"G-CD roger, contact tower 124.0"
"Tower 124.0, G-CD"
"East Mids Tower, G-ABCD zone in Shepshed"
"G-CD report left base for 27, number one"
englishal
What you descibe above is more like what happens (to me anyway!) when I've been into places like Coventry and Cambridge - not class D. However, it was also quite similar to the crossing clearance I got from Luton once. I.e. they did not use the words 'cleared to enter', nor did I. All quite informal and I didn't see that as a problem. But I guess the words "you are cleared" were never spoken - therefore was I really 'cleared'?