Clarify some descriptions

Change-Id: I3177c468eeec3f1de49d6e2d71889c36acf202bc
diff --git a/mbedtls-dockerfile-builder.yaml b/mbedtls-dockerfile-builder.yaml
index 2f614eb..07d73ed 100644
--- a/mbedtls-dockerfile-builder.yaml
+++ b/mbedtls-dockerfile-builder.yaml
@@ -1,6 +1,6 @@
 - job:
     concurrent: true
-    description: Dockerfile building job.
+    description: Dockerfile building job
     disabled: false
     dsl: |-
       timestamps {
@@ -74,12 +74,12 @@
     parameters:
     - string:
         default: ssh://git@github.com/Mbed-TLS/mbedtls-test.git
-        description: Enter mbed TLS test repo/fork
+        description: Mbed TLS test repo/fork
         name: MBED_TLS_TEST_REPO
         trim: 'false'
     - string:
         default: main
-        description: Enter branch or commit to build dockerfile from
+        description: Branch or commit to build Dockerfile from
         name: MBED_TLS_TEST_BRANCH
         trim: 'false'
     - bool:
@@ -88,7 +88,7 @@
         name: BUILD_16_04_DOCKERFILE
     - string:
         default: ubuntu-16.04-testing
-        description: Enter tag for Ubuntu 16.04 Docker image being built
+        description: Tag for the Ubuntu 16.04 Docker image being built
         name: TAG_FOR_16_04_DOCKERFILE
         trim: 'false'
     - bool:
@@ -97,7 +97,7 @@
         name: BUILD_18_04_DOCKERFILE
     - string:
         default: ubuntu-18.04-testing
-        description: Enter tag for Ubuntu 18.04 Docker image being built
+        description: Tag for the Ubuntu 18.04 Docker image being built
         name: TAG_FOR_18_04_DOCKERFILE
         trim: 'false'
     - bool:
@@ -106,7 +106,7 @@
         name: BUILD_20_04_DOCKERFILE
     - string:
         default: ubuntu-20.04-testing
-        description: Enter tag for Ubuntu 20.04 Docker image being built
+        description: Tag for the Ubuntu 20.04 Docker image being built
         name: TAG_FOR_20_04_DOCKERFILE
         trim: 'false'
     project-type: pipeline