Use apple messages --help and subcommand help as the first reference.
Common reads:
apple messages conversations list --json
apple messages search --query "meeting" --json
apple messages read --id MESSAGE_ID --jsonSends use the DryRun safety flow:
apple messages send --to +15555550100 --text "Running late" --dry-run --jsonThe detailed capability boundary lives in
../../Architecture/Messages/CapabilityList.md.