> **Run limitation: no citable sources**
>
> In this run, `paper_search` returned zero results across multiple query formulations, `clinical_trials_search` returned zero trials, and `open_targets_search` failed after retries.
>
> Because no retrievable documents produced any citable context IDs, the system cannot generate the requested PMID-grounded report with citations, URLs, publication dates, and abstract quotes; it also cannot submit a final answer through the answer tool, which requires grounded evidence.
>
> Suggested next steps: enable literature retrieval, ingest authoritative disease resources (OMIM, Orphanet, GeneReviews), and add PubMed-indexed articles or PDFs on EDN3/EDNRB Waardenburg–Shah syndrome so that citable contexts can be created for a complete evidence-backed report.


*Blockquote: This blockquote documents the evidence-retrieval failure in the current run and explains why a properly cited report could not be produced. It also lists the minimum next steps needed to enable a complete, evidence-grounded answer.*