Query was missing or blank.
No web search providers exist in metadata at all — a setup problem, not a search failure.
The provider list could not be READ — the view query failed, the entity is absent from
metadata, or the caller lacks permission. Deliberately distinct from
NO_PROVIDERS_CONFIGURED: that one tells an operator to add a record, which is the wrong
instruction (and an actively misleading one) when the read itself never succeeded.
Providers exist, but none is Active, available and capable of this request.
An explicit Provider was named and no such provider exists in metadata.
The named provider exists but its Status is not Active.
The named provider is Active but not operational — usually a missing credential.
The named provider cannot do what was asked, e.g. IncludeAnswer on a hits-only provider.
Every eligible provider was tried and each failed. See Attempts.
The request itself was rejected and retrying elsewhere cannot help.
Outcome codes.
SUCCESSis the only one where WebSearchResult.Success is true.