diff --git a/src/SQLInsight.Repository/InsightRepository.InstanceConfiguration.cs b/src/SQLInsight.Repository/InsightRepository.InstanceConfiguration.cs
index 1394e18..b03a29d 100644
--- a/src/SQLInsight.Repository/InsightRepository.InstanceConfiguration.cs
+++ b/src/SQLInsight.Repository/InsightRepository.InstanceConfiguration.cs
@@ -307,15 +307,27 @@ public sealed partial class InsightRepository
         return unknown;
     }
 
-    /// <summary>Queues a request for the agent (SQLInsight Web: INSERT only).</summary>
+    /// <summary>
+    /// Queues a request for the agent (SQLInsight Web: INSERT only). The same request still waiting for the agent is
+    /// returned instead of a new one, so pressing the button again (or a script in a loop) does not grow the queue.
+    /// </summary>
     public async Task<long> AddAgentRequestAsync(string kind, int? configuredInstanceId, string? parameters, string? by, DateTimeOffset now,
         CancellationToken cancellationToken = default)
     {
         await using var connection = await OpenAsync(cancellationToken).ConfigureAwait(false);
         return await connection.ExecuteScalarAsync<long>("""
-            INSERT insight.AgentRequests (Kind, ConfiguredInstanceId, Parameters, Status, RequestedBy, RequestedAt)
-            OUTPUT INSERTED.RequestId
-            VALUES (@kind, @configuredInstanceId, @parameters, 'Pending', @by, @now);
+            DECLARE @id bigint = (SELECT TOP (1) RequestId FROM insight.AgentRequests
+                                  WHERE Status = 'Pending' AND Kind = @kind
+                                    AND (ConfiguredInstanceId = @configuredInstanceId OR (@configuredInstanceId IS NULL AND ConfiguredInstanceId IS NULL))
+                                    AND ISNULL(Parameters, N'') = ISNULL(@parameters, N'')
+                                  ORDER BY RequestId DESC);
+            IF @id IS NULL
+            BEGIN
+                INSERT insight.AgentRequests (Kind, ConfiguredInstanceId, Parameters, Status, RequestedBy, RequestedAt)
+                VALUES (@kind, @configuredInstanceId, @parameters, 'Pending', @by, @now);
+                SET @id = SCOPE_IDENTITY();
+            END
+            SELECT @id;
             """, new { kind, configuredInstanceId, parameters, by, now = Utc(now) }).ConfigureAwait(false);
     }