`unknown_pool`

422 Unprocessable Content The requested agent pool does not exist.

When you get it

The requested agent pool does not exist. It is always answered with HTTP 422 - one code means one status, so a client may key its handling on either.

Fields it carries

Inside each errors[] entry, beside pointer:

pool: The agent pool that was named.
valid: Valid values, possibly capped - see `validCount` and `validTruncated`.
validCount: How many valid values exist in total, when `valid` was capped.
validTruncated: True when `valid` is a prefix rather than the exhaustive set.

A field is omitted when the server genuinely does not know it - an absent member is never the same as an empty one.

How to fix it

The request was well-formed but a value is not acceptable. The fields above name the offending value and what would be accepted - fix the request and retry.

Shape

{
  "type":   "https://api2.host-tracker.com/problems/unknown-pool",
  "title":  "The requested agent pool does not exist.",
  "status": 422,
  "code":   "unknown_pool",
  "errors": [
    { "pool": …, "valid": …, "validCount": …, "validTruncated": … }
  ]
}