Execute the same GraphQL query multiple times with different variable sets.

Use this tool instead of the regular query tool when you need to run the same query
repeatedly with different arguments (e.g., querying multiple drugs, targets, or diseases).

WORKFLOW - Follow these steps in order:

Step 1: RESOLVE IDENTIFIERS
    If user provides common names (gene symbols, disease names, drug names),
    use `search_entity` tool FIRST to convert them to standardized IDs:

    - Targets/Genes: "BRCA1", "BRCA2" -> ENSEMBL IDs "ENSG00000012048", "ENSG00000139618"
    - Diseases: "breast cancer" -> EFO/MONDO ID "MONDO_0007254"
    - Drugs: "aspirin", "ibuprofen" -> ChEMBL IDs "CHEMBL1201583", "CHEMBL521"
    - Variants: Use "chr_pos_ref_alt" format or rsIDs

    Example: search_entity(query_string="BRCA1 BRCA2", entity_names=["target"])

Step 2: LEARN QUERY STRUCTURE
    Call `get_open_targets_graphql_schema` to retrieve the full API schema.
    Study the schema to understand available types, fields, and their
    relationships, then construct a GraphQL query that fetches the
    information the user needs.

Step 3: CONSTRUCT AND EXECUTE BATCH QUERY
    Build GraphQL query and variables_list using:
    - Standardized IDs from Step 1 (REQUIRED)
    - Query patterns from Step 2

    Call this tool with query_string, variables_list, and key_field.

REQUIRED IDENTIFIER FORMATS:
- Targets/Genes: ENSEMBL IDs (e.g., "ENSG00000139618")
- Diseases: EFO IDs (e.g., "EFO_0000305") or MONDO IDs (e.g., "MONDO_0007254")
- Drugs: ChEMBL IDs (e.g., "CHEMBL1201583")
- Variants: "chr_pos_ref_alt" format (e.g., "19_44908822_C_T") or rsIDs (e.g., "rs7412")
- Studies: Study IDs (e.g., "GCST90002357")
- Credible Sets: Study Locus IDs (e.g., "7d68cc9c70351c9dbd2a2c0c145e555d")

Args:
    query_string: The GraphQL query string to execute for all variable sets
    variables_list: List of variable dictionaries, one per query execution
    key_field: Variable field name to use as key in results mapping (e.g., "chemblId")

Returns:
    dict: Results keyed by the specified field value, with execution summary:
        {
            "status": "success",
            "results": {
                "<key_value>": {"status": "success", "data": ...},
                ...
            },
            "summary": {"total": <int>, "successful": <int>, "failed": <int>}
        }