Enum values changed in POST /v1/messages/count_tokens?beta=true (BetaAdvisorToolResultErrorCode)

What changed

Enum values changed in POST /v1/messages/count_tokens?beta=true (BetaAdvisorToolResultErrorCode) Affected surface: POST /v1/messages/count_tokens?beta=true. Root cause: schema `BetaAdvisorToolResultErrorCode`. Detected at Sun, 07 Jun 2026 02:08:27 UTC UTC.

Diff

{
  "added_enums": [
    "model_not_found"
  ],
  "path": "POST /v1/messages/count_tokens?beta=true",
  "schema_path": "schema BetaAdvisorToolResultErrorCode"
}

Likely impact

This is an additive change. Existing integrations are unaffected; this is mostly useful if you want to take advantage of the new surface.

Recommended action

Audit any switch/match statements over this enum. Removed values become unhandled paths.