diff --git a/lib/ecto_psql_extras.ex b/lib/ecto_psql_extras.ex
index 3641a99..2844dda 100644
--- a/lib/ecto_psql_extras.ex
+++ b/lib/ecto_psql_extras.ex
@@ -6,6 +6,14 @@ defmodule EctoPSQLExtras do
   @callback info :: %{
               required(:title) => binary,
               required(:columns) => [%{name: atom, type: atom}],
+              required(:parameters) => [
+                %{
+                  required(:name) => atom,
+                  required(:type) => atom,
+                  optional(:default) => term,
+                  optional(:description) => binary
+                }
+              ],
               optional(:order_by) => [{atom, :asc | :desc}],
               optional(:index) => integer,
               optional(:default_args) => list,
diff --git a/lib/queries/all_locks.ex b/lib/queries/all_locks.ex
index 43ae9cd..b024d94 100644
--- a/lib/queries/all_locks.ex
+++ b/lib/queries/all_locks.ex
@@ -13,7 +13,8 @@ defmodule EctoPSQLExtras.AllLocks do
         %{name: :query_snippet, type: :string},
         %{name: :mode, type: :string},
         %{name: :age, type: :interval}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/bloat.ex b/lib/queries/bloat.ex
index 6925d75..146f758 100644
--- a/lib/queries/bloat.ex
+++ b/lib/queries/bloat.ex
@@ -12,7 +12,8 @@ defmodule EctoPSQLExtras.Bloat do
         %{name: :object_name, type: :string},
         %{name: :bloat, type: :numeric},
         %{name: :waste, type: :bytes}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/blocking.ex b/lib/queries/blocking.ex
index 699884f..f17f570 100644
--- a/lib/queries/blocking.ex
+++ b/lib/queries/blocking.ex
@@ -12,7 +12,8 @@ defmodule EctoPSQLExtras.Blocking do
         %{name: :blocking_pid, type: :integer},
         %{name: :blocked_statement, type: :string},
         %{name: :blocked_duration, type: :interval}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/cache_hit.ex b/lib/queries/cache_hit.ex
index 9805f6b..6824af1 100644
--- a/lib/queries/cache_hit.ex
+++ b/lib/queries/cache_hit.ex
@@ -8,7 +8,8 @@ defmodule EctoPSQLExtras.CacheHit do
       columns: [
         %{name: :name, type: :string},
         %{name: :ratio, type: :numeric}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/calls.ex b/lib/queries/calls.ex
index a80669c..0df20a7 100644
--- a/lib/queries/calls.ex
+++ b/lib/queries/calls.ex
@@ -13,6 +13,14 @@ defmodule EctoPSQLExtras.Calls do
         %{name: :prop_exec_time, type: :percent},
         %{name: :calls, type: :integer},
         %{name: :sync_io_time, type: :interval}
+      ],
+      parameters: [
+        %{
+          name: :limit,
+          type: :integer,
+          default: 10,
+          description: "Maximum queries to return."
+        }
       ]
     }
   end
diff --git a/lib/queries/calls_17.ex b/lib/queries/calls_17.ex
index b0b7ddf..a7d290d 100644
--- a/lib/queries/calls_17.ex
+++ b/lib/queries/calls_17.ex
@@ -13,6 +13,14 @@ defmodule EctoPSQLExtras.Calls17 do
         %{name: :prop_exec_time, type: :percent},
         %{name: :calls, type: :integer},
         %{name: :sync_io_time, type: :interval}
+      ],
+      parameters: [
+        %{
+          name: :limit,
+          type: :integer,
+          default: 10,
+          description: "Maximum queries to return."
+        }
       ]
     }
   end
diff --git a/lib/queries/calls_legacy.ex b/lib/queries/calls_legacy.ex
index 502a628..94d5856 100644
--- a/lib/queries/calls_legacy.ex
+++ b/lib/queries/calls_legacy.ex
@@ -12,6 +12,14 @@ defmodule EctoPSQLExtras.CallsLegacy do
         %{name: :prop_exec_time, type: :percent},
         %{name: :calls, type: :integer},
         %{name: :sync_io_time, type: :interval}
+      ],
+      parameters: [
+        %{
+          name: :limit,
+          type: :integer,
+          default: 10,
+          description: "Maximum queries to return."
+        }
       ]
     }
   end
diff --git a/lib/queries/connections.ex b/lib/queries/connections.ex
index 6b01ea5..c86b3de 100644
--- a/lib/queries/connections.ex
+++ b/lib/queries/connections.ex
@@ -8,7 +8,8 @@ defmodule EctoPSQLExtras.Connections do
         %{name: :username, type: :string},
         %{name: :client_address, type: :string},
         %{name: :application_name, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/db_settings.ex b/lib/queries/db_settings.ex
index 5629583..b3a7792 100644
--- a/lib/queries/db_settings.ex
+++ b/lib/queries/db_settings.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.DbSettings do
         %{name: :setting, type: :string},
         %{name: :unit, type: :string},
         %{name: :short_desc, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/diagnose.ex b/lib/queries/diagnose.ex
index 31015ef..4a84057 100644
--- a/lib/queries/diagnose.ex
+++ b/lib/queries/diagnose.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.Diagnose do
         %{name: :ok, type: :boolean},
         %{name: :check_name, type: :string},
         %{name: :message, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/duplicate_indexes.ex b/lib/queries/duplicate_indexes.ex
index 4ed7dc1..9681a88 100644
--- a/lib/queries/duplicate_indexes.ex
+++ b/lib/queries/duplicate_indexes.ex
@@ -12,7 +12,8 @@ defmodule EctoPSQLExtras.DuplicateIndexes do
         %{name: :idx2, type: :string},
         %{name: :idx3, type: :string},
         %{name: :idx4, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/extensions.ex b/lib/queries/extensions.ex
index ec1a6f2..a00e0ac 100644
--- a/lib/queries/extensions.ex
+++ b/lib/queries/extensions.ex
@@ -11,7 +11,8 @@ defmodule EctoPSQLExtras.Extensions do
         %{name: :default_version, type: :string},
         %{name: :installed_version, type: :string},
         %{name: :comment, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/index_cache_hit.ex b/lib/queries/index_cache_hit.ex
index 6ffb964..2432ea9 100644
--- a/lib/queries/index_cache_hit.ex
+++ b/lib/queries/index_cache_hit.ex
@@ -13,7 +13,8 @@ defmodule EctoPSQLExtras.IndexCacheHit do
         %{name: :block_reads, type: :integer},
         %{name: :total_read, type: :integer},
         %{name: :ratio, type: :numeric}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/index_size.ex b/lib/queries/index_size.ex
index 61834f3..ed9d4e5 100644
--- a/lib/queries/index_size.ex
+++ b/lib/queries/index_size.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.IndexSize do
         %{name: :schema, type: :string},
         %{name: :name, type: :string},
         %{name: :size, type: :bytes}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/index_usage.ex b/lib/queries/index_usage.ex
index 36ef701..f0c2573 100644
--- a/lib/queries/index_usage.ex
+++ b/lib/queries/index_usage.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.IndexUsage do
         %{name: :name, type: :string},
         %{name: :percent_of_times_index_used, type: :numeric},
         %{name: :rows_in_table, type: :int}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/indexes.ex b/lib/queries/indexes.ex
index b0ef27b..3abc299 100644
--- a/lib/queries/indexes.ex
+++ b/lib/queries/indexes.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.Indexes do
         %{name: :indexname, type: :string},
         %{name: :tablename, type: :string},
         %{name: :columns, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/kill_all.ex b/lib/queries/kill_all.ex
index 5a306fa..f02b423 100644
--- a/lib/queries/kill_all.ex
+++ b/lib/queries/kill_all.ex
@@ -6,7 +6,8 @@ defmodule EctoPSQLExtras.KillAll do
       title: "Kill all the active database connections",
       columns: [
         %{name: :killed, type: :boolean}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/locks.ex b/lib/queries/locks.ex
index f5f3fa2..9e123a0 100644
--- a/lib/queries/locks.ex
+++ b/lib/queries/locks.ex
@@ -13,7 +13,8 @@ defmodule EctoPSQLExtras.Locks do
         %{name: :query_snippet, type: :string},
         %{name: :mode, type: :string},
         %{name: :age, type: :interval}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/long_running_queries.ex b/lib/queries/long_running_queries.ex
index 8585d13..bba64ff 100644
--- a/lib/queries/long_running_queries.ex
+++ b/lib/queries/long_running_queries.ex
@@ -11,6 +11,14 @@ defmodule EctoPSQLExtras.LongRunningQueries do
         %{name: :pid, type: :int},
         %{name: :duration, type: :interval},
         %{name: :query, type: :string}
+      ],
+      parameters: [
+        %{
+          name: :threshold,
+          type: :string,
+          default: "500 milliseconds",
+          description: "Minimum query duration."
+        }
       ]
     }
   end
diff --git a/lib/queries/null_indexes.ex b/lib/queries/null_indexes.ex
index 8db7768..ab4fa16 100644
--- a/lib/queries/null_indexes.ex
+++ b/lib/queries/null_indexes.ex
@@ -14,6 +14,14 @@ defmodule EctoPSQLExtras.NullIndexes do
         %{name: :indexed_column, type: :string},
         %{name: :null_frac, type: :string},
         %{name: :expected_saving, type: :string}
+      ],
+      parameters: [
+        %{
+          name: :min_relation_size_mb,
+          type: :integer,
+          default: 0,
+          description: "Minimum relation size in megabytes."
+        }
       ]
     }
   end
diff --git a/lib/queries/outliers.ex b/lib/queries/outliers.ex
index 9d11067..6f32c78 100644
--- a/lib/queries/outliers.ex
+++ b/lib/queries/outliers.ex
@@ -13,6 +13,14 @@ defmodule EctoPSQLExtras.Outliers do
         %{name: :prop_exec_time, type: :percent},
         %{name: :calls, type: :integer},
         %{name: :sync_io_time, type: :interval}
+      ],
+      parameters: [
+        %{
+          name: :limit,
+          type: :integer,
+          default: 10,
+          description: "Maximum queries to return."
+        }
       ]
     }
   end
diff --git a/lib/queries/outliers_17.ex b/lib/queries/outliers_17.ex
index a6bd8ab..a12a682 100644
--- a/lib/queries/outliers_17.ex
+++ b/lib/queries/outliers_17.ex
@@ -13,6 +13,14 @@ defmodule EctoPSQLExtras.Outliers17 do
         %{name: :prop_exec_time, type: :percent},
         %{name: :calls, type: :integer},
         %{name: :sync_io_time, type: :interval}
+      ],
+      parameters: [
+        %{
+          name: :limit,
+          type: :integer,
+          default: 10,
+          description: "Maximum queries to return."
+        }
       ]
     }
   end
diff --git a/lib/queries/outliers_legacy.ex b/lib/queries/outliers_legacy.ex
index 6e51426..b7f16f2 100644
--- a/lib/queries/outliers_legacy.ex
+++ b/lib/queries/outliers_legacy.ex
@@ -13,6 +13,14 @@ defmodule EctoPSQLExtras.OutliersLegacy do
         %{name: :prop_exec_time, type: :percent},
         %{name: :calls, type: :integer},
         %{name: :sync_io_time, type: :interval}
+      ],
+      parameters: [
+        %{
+          name: :limit,
+          type: :integer,
+          default: 10,
+          description: "Maximum queries to return."
+        }
       ]
     }
   end
diff --git a/lib/queries/records_rank.ex b/lib/queries/records_rank.ex
index de09523..8b6c382 100644
--- a/lib/queries/records_rank.ex
+++ b/lib/queries/records_rank.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.RecordsRank do
         %{name: :schema, type: :string},
         %{name: :name, type: :string},
         %{name: :estimated_count, type: :integer}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/seq_scans.ex b/lib/queries/seq_scans.ex
index bb612d7..af126fd 100644
--- a/lib/queries/seq_scans.ex
+++ b/lib/queries/seq_scans.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.SeqScans do
         %{name: :schema, type: :string},
         %{name: :name, type: :string},
         %{name: :count, type: :integer}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/ssl_used.ex b/lib/queries/ssl_used.ex
index f0a1bd3..ae4fdcf 100644
--- a/lib/queries/ssl_used.ex
+++ b/lib/queries/ssl_used.ex
@@ -7,7 +7,8 @@ defmodule EctoPSQLExtras.SSLUsed do
       index: 9,
       columns: [
         %{name: :ssl_is_used, type: :boolean}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/table_cache_hit.ex b/lib/queries/table_cache_hit.ex
index db63d81..e4d950a 100644
--- a/lib/queries/table_cache_hit.ex
+++ b/lib/queries/table_cache_hit.ex
@@ -13,7 +13,8 @@ defmodule EctoPSQLExtras.TableCacheHit do
         %{name: :block_reads, type: :integer},
         %{name: :total_read, type: :integer},
         %{name: :ratio, type: :numeric}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/table_foreign_keys.ex b/lib/queries/table_foreign_keys.ex
index 0ffd452..9b9f145 100644
--- a/lib/queries/table_foreign_keys.ex
+++ b/lib/queries/table_foreign_keys.ex
@@ -4,12 +4,20 @@ defmodule EctoPSQLExtras.TableForeignKeys do
   def info do
     %{
       title: "Foreign keys info",
+      default_args: [table_name: nil],
       columns: [
         %{name: :table_name, type: :string},
         %{name: :constraint_name, type: :string},
         %{name: :column_name, type: :string},
         %{name: :foreign_table_name, type: :string},
         %{name: :foreign_column_name, type: :string}
+      ],
+      parameters: [
+        %{
+          name: :table_name,
+          type: :string,
+          description: "Filter foreign keys by table name. Omit to search all tables."
+        }
       ]
     }
   end
diff --git a/lib/queries/table_indexes_size.ex b/lib/queries/table_indexes_size.ex
index 49df2fa..76285d2 100644
--- a/lib/queries/table_indexes_size.ex
+++ b/lib/queries/table_indexes_size.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.TableIndexesSize do
         %{name: :schema, type: :string},
         %{name: :table, type: :string},
         %{name: :index_size, type: :bytes}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/table_schema.ex b/lib/queries/table_schema.ex
index 9c152e7..775cf2c 100644
--- a/lib/queries/table_schema.ex
+++ b/lib/queries/table_schema.ex
@@ -4,12 +4,20 @@ defmodule EctoPSQLExtras.TableSchema do
   def info do
     %{
       title: "Column names and types",
+      default_args: [table_name: nil],
       columns: [
         %{name: :column_name, type: :string},
         %{name: :data_type, type: :string},
         %{name: :is_nullable, type: :boolean},
         %{name: :column_default, type: :string},
         %{name: :table_name, type: :string}
+      ],
+      parameters: [
+        %{
+          name: :table_name,
+          type: :string,
+          description: "Filter results by table name. Omit to search all tables."
+        }
       ]
     }
   end
diff --git a/lib/queries/table_size.ex b/lib/queries/table_size.ex
index cb6ccdc..a1c221c 100644
--- a/lib/queries/table_size.ex
+++ b/lib/queries/table_size.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.TableSize do
         %{name: :schema, type: :string},
         %{name: :name, type: :string},
         %{name: :size, type: :bytes}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/total_index_size.ex b/lib/queries/total_index_size.ex
index 487dd3d..1c9f8fa 100644
--- a/lib/queries/total_index_size.ex
+++ b/lib/queries/total_index_size.ex
@@ -7,7 +7,8 @@ defmodule EctoPSQLExtras.TotalIndexSize do
       index: 13,
       columns: [
         %{name: :size, type: :bytes}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/total_table_size.ex b/lib/queries/total_table_size.ex
index cc7f230..5f9c10b 100644
--- a/lib/queries/total_table_size.ex
+++ b/lib/queries/total_table_size.ex
@@ -10,7 +10,8 @@ defmodule EctoPSQLExtras.TotalTableSize do
         %{name: :schema, type: :string},
         %{name: :name, type: :string},
         %{name: :size, type: :bytes}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/lib/queries/unused_indexes.ex b/lib/queries/unused_indexes.ex
index a883db4..9715fb5 100644
--- a/lib/queries/unused_indexes.ex
+++ b/lib/queries/unused_indexes.ex
@@ -12,6 +12,14 @@ defmodule EctoPSQLExtras.UnusedIndexes do
         %{name: :index, type: :string},
         %{name: :index_size, type: :bytes},
         %{name: :index_scans, type: :integer}
+      ],
+      parameters: [
+        %{
+          name: :min_scans,
+          type: :integer,
+          default: 50,
+          description: "Filter results with at least this many scans."
+        }
       ]
     }
   end
diff --git a/lib/queries/vacuum_stats.ex b/lib/queries/vacuum_stats.ex
index 56379e1..bce996b 100644
--- a/lib/queries/vacuum_stats.ex
+++ b/lib/queries/vacuum_stats.ex
@@ -14,7 +14,8 @@ defmodule EctoPSQLExtras.VacuumStats do
         %{name: :dead_rowcount, type: :string},
         %{name: :autovacuum_threshold, type: :string},
         %{name: :expect_autovacuum, type: :string}
-      ]
+      ],
+      parameters: []
     }
   end
 
diff --git a/test/ecto_psql_extras_test.exs b/test/ecto_psql_extras_test.exs
index 9ded40d..edfb391 100644
--- a/test/ecto_psql_extras_test.exs
+++ b/test/ecto_psql_extras_test.exs
@@ -27,6 +27,14 @@ defmodule EctoPSQLExtrasTest do
         assert column.type
       end
 
+      assert is_list(info.parameters)
+
+      for parameter <- info.parameters do
+        assert is_atom(parameter.name)
+        assert is_atom(parameter.type)
+        assert Map.keys(parameter) -- [:name, :type, :default, :description] == []
+      end
+
       for {order_by, dir} <- info[:order_by] || [] do
         assert dir in [:asc, :desc]
         assert Enum.find(info.columns, &(&1.name == order_by))