diff --git a/src/tools/__init__.py b/src/tools/__init__.py
index 27c4946..6aef142 100644
--- a/src/tools/__init__.py
+++ b/src/tools/__init__.py
@@ -16,7 +16,14 @@
 
 # Query tools
 from .query import (
+    get_queries_not_selective,
+    get_queries_not_using_covering_index,
+    get_queries_using_primary_index,
+    get_queries_with_large_result_count,
+    get_queries_with_largest_response_sizes,
     get_schema_for_collection,
+    get_top_longest_running_queries,
+    get_top_most_frequent_queries,
     run_sql_plus_plus_query,
 )
 
@@ -47,6 +54,13 @@
     get_index_advisor_recommendations,
     list_indexes,
     get_cluster_health_and_services,
+    get_queries_not_selective,
+    get_queries_not_using_covering_index,
+    get_queries_using_primary_index,
+    get_queries_with_large_result_count,
+    get_queries_with_largest_response_sizes,
+    get_top_longest_running_queries,
+    get_top_most_frequent_queries,
 ]
 
 __all__ = [
@@ -65,6 +79,13 @@
     "get_index_advisor_recommendations",
     "list_indexes",
     "get_cluster_health_and_services",
+    "get_queries_not_selective",
+    "get_queries_not_using_covering_index",
+    "get_queries_using_primary_index",
+    "get_queries_with_large_result_count",
+    "get_queries_with_largest_response_sizes",
+    "get_top_longest_running_queries",
+    "get_top_most_frequent_queries",
     # Convenience
     "ALL_TOOLS",
 ]
diff --git a/src/tools/query.py b/src/tools/query.py
index d6a44d7..c09e7c6 100644
--- a/src/tools/query.py
+++ b/src/tools/query.py
@@ -81,7 +81,6 @@ def run_sql_plus_plus_query(
         raise
 
 
-# Don't expose this function to the MCP server until we have a use case
 def run_cluster_query(ctx: Context, query: str, **kwargs: Any) -> list[dict[str, Any]]:
     """Run a query on the cluster object and return the results as a list of JSON objects."""
 
@@ -96,3 +95,185 @@ def run_cluster_query(ctx: Context, query: str, **kwargs: Any) -> list[dict[str,
     except Exception as e:
         logger.error(f"Error running query: {e}")
         raise
+
+
+def get_top_longest_running_queries(
+    ctx: Context, limit: int = 10
+) -> list[dict[str, Any]]:
+    """Get the top N longest running queries from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries with their average service time and count
+    """
+    query = """
+    SELECT statement,
+        DURATION_TO_STR(avgServiceTime) AS avgServiceTime,
+        COUNT(1) AS queries
+    FROM system:completed_requests
+    WHERE UPPER(statement) NOT LIKE 'INFER %'
+        AND UPPER(statement) NOT LIKE 'CREATE INDEX%'
+        AND UPPER(statement) NOT LIKE '% SYSTEM:%'
+    GROUP BY statement
+    LETTING avgServiceTime = AVG(STR_TO_DURATION(serviceTime))
+    ORDER BY avgServiceTime DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)
+
+
+def get_top_most_frequent_queries(
+    ctx: Context, limit: int = 10
+) -> list[dict[str, Any]]:
+    """Get the top N most frequent queries from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries with their frequency count
+    """
+    query = """
+    SELECT statement,
+        COUNT(1) AS queries
+    FROM system:completed_requests
+    WHERE UPPER(statement) NOT LIKE 'INFER %'
+        AND UPPER(statement) NOT LIKE 'CREATE INDEX%'
+        AND UPPER(statement) NOT LIKE '% SYSTEM:%'
+    GROUP BY statement
+    LETTING queries = COUNT(1)
+    ORDER BY queries DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)
+
+
+def get_queries_with_largest_response_sizes(
+    ctx: Context, limit: int = 10
+) -> list[dict[str, Any]]:
+    """Get queries with the largest response sizes from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries with their average result size in bytes, KB, and MB
+    """
+    query = """
+    SELECT statement,
+        avgResultSize AS avgResultSizeBytes,
+        (avgResultSize / 1000) AS avgResultSizeKB,
+        (avgResultSize / 1000000) AS avgResultSizeMB,
+        COUNT(1) AS queries
+    FROM system:completed_requests
+    WHERE UPPER(statement) NOT LIKE 'INFER %'
+        AND UPPER(statement) NOT LIKE 'CREATE INDEX%'
+        AND UPPER(statement) NOT LIKE '% SYSTEM:%'
+    GROUP BY statement
+    LETTING avgResultSize = AVG(resultSize)
+    ORDER BY avgResultSize DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)
+
+
+def get_queries_with_large_result_count(
+    ctx: Context, limit: int = 10
+) -> list[dict[str, Any]]:
+    """Get queries with the largest result counts from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries with their average result count
+    """
+    query = """
+    SELECT statement,
+        avgResultCount,
+        COUNT(1) AS queries
+    FROM system:completed_requests
+    WHERE UPPER(statement) NOT LIKE 'INFER %'
+        AND UPPER(statement) NOT LIKE 'CREATE INDEX%'
+        AND UPPER(statement) NOT LIKE '% SYSTEM:%'
+    GROUP BY statement
+    LETTING avgResultCount = AVG(resultCount)
+    ORDER BY avgResultCount DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)
+
+
+def get_queries_using_primary_index(
+    ctx: Context, limit: int = 10
+) -> list[dict[str, Any]]:
+    """Get queries that use a primary index from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries that use primary indexes, ordered by result count
+    """
+    query = """
+    SELECT *
+    FROM system:completed_requests
+    WHERE phaseCounts.`primaryScan` IS NOT MISSING
+        AND UPPER(statement) NOT LIKE '% SYSTEM:%'
+    ORDER BY resultCount DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)
+
+
+def get_queries_not_using_covering_index(
+    ctx: Context, limit: int = 10
+) -> list[dict[str, Any]]:
+    """Get queries that don't use a covering index from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries that perform index scans but also require fetches (not covering)
+    """
+    query = """
+    SELECT *
+    FROM system:completed_requests
+    WHERE phaseCounts.`indexScan` IS NOT MISSING
+        AND phaseCounts.`fetch` IS NOT MISSING
+        AND UPPER(statement) NOT LIKE '% SYSTEM:%'
+    ORDER BY resultCount DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)
+
+
+def get_queries_not_selective(ctx: Context, limit: int = 10) -> list[dict[str, Any]]:
+    """Get queries that are not very selective from the system:completed_requests catalog.
+
+    Args:
+        limit: Number of queries to return (default: 10)
+
+    Returns:
+        List of queries where index scans return significantly more documents than the final result
+    """
+    query = """
+    SELECT statement,
+       AVG(phaseCounts.`indexScan` - resultCount) AS diff
+    FROM system:completed_requests
+    WHERE phaseCounts.`indexScan` > resultCount
+    GROUP BY statement
+    ORDER BY diff DESC
+    LIMIT $limit
+    """
+
+    return run_cluster_query(ctx, query, limit=limit)