title: How to parameterize agent pool name in azure pipeline with yaml file
body: <p>Hi I am using agent pool in azure pipeline, so i have multiple agents so i want to parameterize the pool name like shown below but when i do this i get an error as (Line: 11, Col: 9): A template expression is not allowed in this context</p>
  <pre><code>parameters:
    - name: pool_name
      displayName: agent pool location
      type: string
      default: test-ashish
  
  trigger:
  - none
  
  pool:
    name: ${{parameters.pool_name}}
    demands: 
    - Location -equals EASTUS2
  
  steps:
  - script: |
      echo &quot;This job is only for testing&quot;
      echo $()
    name: Test_Job
    displayName: Test Job
  </code></pre>