Update specify.md

Author: localden

templates/commands/specify.md

@@ -8,6 +8,7 @@ scripts:
 Given the feature description provided as an argument, do this:
 
 1. Run the script `{SCRIPT}` from repo root and parse its JSON output for BRANCH_NAME and SPEC_FILE. All file paths must be absolute.
+  **IMPORTANT** You must only ever run this script once. The JSON is provided in the terminal as output - always refer to it to get the actual content you're looking for.
 2. Load `templates/spec-template.md` to understand required sections.
 3. Write the specification to SPEC_FILE using the template structure, replacing placeholders with concrete details derived from the feature description (arguments) while preserving section order and headings.
 4. Report completion with branch name, spec file path, and readiness for the next phase.