Amend comments per review

go/codeql-extractor.yml

@@ -21,9 +21,9 @@ file_types:
 legacy_qltest_extraction: true
 options:
   extract_tests:
-    title: Whether to include Go test files and functions in the CodeQL database.
+    title: Whether to include Go test files in the CodeQL database.
     description: >
-      A value indicating whether Go test files and functions should be included in the CodeQL database.
+      A value indicating whether Go test files should be included in the CodeQL database.
       The default is 'false'.
     type: string
     pattern: "^(false|true)$"

go/extractor/cli/go-extractor/go-extractor.go

@@ -21,6 +21,8 @@ func usage() {
 	fmt.Fprintf(os.Stderr, "--help                Print this help.\n")
 }
 
+// extractTests is set (a) if we were manually commanded to extract tests via the relevant
+// environment variable / extractor option, or (b) we're mimicking a `go test` command.
 func parseFlags(args []string, mimic bool, extractTests bool) ([]string, []string, bool) {
 	i := 0
 	buildFlags := []string{}

go/extractor/toolchain/toolchain.go

@@ -232,6 +232,7 @@ func GetPkgsInfo(patterns []string, includingDeps bool, extractTests bool, flags
 	}
 
 	if extractTests {
+		// Without the `-test` flag, test packages would be omitted from the `go list` output.
 		flags = append(flags, "-test")
 	}