output script descriptors – `getdescriptorinfo` for private key

Public key:

bitcoin-cli getdescriptorinfo "wpkh(027fda10f37e6c637a1cfeba2cbada86de36f28e63d4ded9e1314117739f6419a9)"
{
  "descriptor": "wpkh(027fda10f37e6c637a1cfeba2cbada86de36f28e63d4ded9e1314117739f6419a9)#99knjm9r",
  "checksum": "99knjm9r",
  "isrange": false,
  "issolvable": true,
  "hasprivatekeys": false
}

Private key:

bitcoin-cli getdescriptorinfo "wpkh(cRLX3mChef5FEFi6y46yH1YJ4Cy7K3WW4bJDBZ7LiygKp4CBsF6p)"
{
  "descriptor": "wpkh(027fda10f37e6c637a1cfeba2cbada86de36f28e63d4ded9e1314117739f6419a9)#99knjm9r",
  "checksum": "s5qjl8cq",
  "isrange": false,
  "issolvable": true,
  "hasprivatekeys": true
}
  1. What is the correct way to use private keys in descriptors?
  2. Why are two checksums returned in getdescriptorinfo for private key?
  3. Why does the KEY inside parenthesis change when using private key with getdescriptorinfo?