## Context
Keyword search fails with 'Request failed with status code 500: An error occurred during the keyword search' when include_domains is specified; removing it succeeds.

## Verified resolution
Contributor jeffzwang: it fails when more than one domain is given - keyword search cannot support multiple domains. Reporter confirmed it works with exactly 1 domain. Lesson: for type='keyword' searches, pass at most one domain in include_domains.