Merge pull request #458 from itkonen/fix-mcp-routing-openai-strict

Fix MCP routing and OpenAI optional tool params

Author: ericdallo

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Bugfix: OpenAI Responses tool calls now opt out of strict schema normalization so optional tool parameters remain optional.
+- Bugfix: MCP tool calls now route to the selected server when multiple servers expose the same tool name.
 - Use a JSON-RPC `ping` (instead of `initialize`) for the OAuth auth-discovery probe, so the probe POST is never counted as a real handshake by servers or tests that track requests by method name.
 
 ## 0.134.1

src/eca/features/tools.clj

@@ -256,10 +256,10 @@
                                                            :call-state-fn call-state-fn
                                                            :state-transition-fn state-transition-fn
                                                            :trust trust})
-                           (f.mcp/call-tool! tool-name arguments {:db db
-                                                                  :db* db*
-                                                                  :config config
-                                                                  :metrics metrics})))
+                           (f.mcp/call-tool! server-name tool-name arguments {:db db
+                                                                              :db* db*
+                                                                              :config config
+                                                                              :metrics metrics})))
                        (tools.util/maybe-truncate-output config tool-call-id))]
         (logger/debug logger-tag "Tool call result: " result)
         (metrics/count-up! "tool-called" {:name resolved-full-name :error (:error result)} metrics)

src/eca/features/tools/mcp.clj

@@ -860,13 +860,11 @@
     (do-call-tool new-client name arguments nil)
     (tool-call-error (format "Failed to re-initialize MCP server '%s'" server-name))))
 
-(defn call-tool! [name arguments {:keys [db db* config metrics]}]
-  (if-let [[server-name mcp-client needs-reinit?*]
-           (->> (:mcp-clients db)
-                (keep (fn [[sn {:keys [client tools needs-reinit?*]}]]
-                        (when (some #(= name (:name %)) tools)
-                          [sn client needs-reinit?*])))
-                first)]
+(defn call-tool! [server-name name arguments {:keys [db db* config metrics]}]
+  (if-let [[mcp-client needs-reinit?*]
+           (when-let [{:keys [client tools needs-reinit?*]} (get-in db [:mcp-clients server-name])]
+             (when (some #(= name (:name %)) tools)
+               [client needs-reinit?*]))]
     (if (and needs-reinit?* @needs-reinit?* db* config metrics)
       ;; Already flagged — reinit before attempting the call
       (reinit-and-call-tool! server-name mcp-client db* config metrics name arguments)
@@ -881,7 +879,7 @@
           (reinit-and-call-tool! server-name mcp-client db* config metrics name arguments)
 
           :else result)))
-    (tool-call-error (format "Tool '%s' not found in any connected MCP server" name))))
+    (tool-call-error (format "Tool '%s' not found in MCP server '%s'" name server-name))))
 
 (defn all-prompts [db]
   (into []

src/eca/features/tools/mcp/clojure_mcp.clj

@@ -9,7 +9,7 @@
   (when (not= "0.1.0" (:version server))
     (when ask-approval?
       (let [path (get args "file_path")
-            {:keys [error contents]} (f.mcp/call-tool! name (assoc args "dry_run" "new-source") {:db db})]
+            {:keys [error contents]} (f.mcp/call-tool! (:name server) name (assoc args "dry_run" "new-source") {:db db})]
         (when-not error
           (when-let [new-source (some->> contents (filter #(= :text (:type %))) first :text)]
             (let [{:keys [added removed diff]} (diff/diff (if new-file?

src/eca/llm_providers/openai.clj

@@ -183,7 +183,8 @@
            {:type "function"
             :name (:full-name tool)
             :description (:description tool)
-            :parameters (:parameters tool)})
+            :parameters (:parameters tool)
+            :strict false})
          tools)
     web-search (conj {:type "web_search"})
     image-generation (conj {:type "image_generation" :output_format "png"})))

test/eca/features/tools/mcp_test.clj

@@ -46,6 +46,30 @@
              (mcp/all-tools {:mcp-clients {"server1" {:tools tools1}
                                            "server2" {:tools tools2}}}))))))
 
+(deftest call-tool-routes-to-server-test
+  (testing "uses the requested MCP server when tool names collide"
+    (let [db {:mcp-clients (array-map
+                            "server-a" {:client :client-a
+                                        :tools [{:name "shared_tool"}]}
+                            "server-b" {:client :client-b
+                                        :tools [{:name "shared_tool"}]})}
+          calls* (atom [])]
+      (with-redefs [mcp/do-call-tool (fn [client name arguments needs-reinit?*]
+                                         (swap! calls* conj {:client client
+                                                            :name name
+                                                            :arguments arguments
+                                                            :needs-reinit?* needs-reinit?*})
+                                         {:error false
+                                          :contents [{:type :text :text (str client)}]})]
+        (is (= {:error false
+                :contents [{:type :text :text ":client-b"}]}
+               (mcp/call-tool! "server-b" "shared_tool" {"query" "value"} {:db db})))
+        (is (= [{:client :client-b
+                 :name "shared_tool"
+                 :arguments {"query" "value"}
+                 :needs-reinit?* nil}]
+               @calls*))))))
+
 (deftest all-prompts-test
   (testing "empty db"
     (is (= []

test/eca/llm_providers/openai_test.clj

@@ -409,7 +409,20 @@
           {:type "image_generation" :output_format "png"}]
          (#'llm-providers.openai/->tools
           [{:full-name "eca__foo" :description "d" :parameters {}}]
-          true true)))))
+          true true))))
+  (testing "function tools explicitly opt out of Responses strict mode"
+    (is (= [{:type "function"
+             :name "mcp__search_records"
+             :description "Search records"
+             :parameters {:type "object"
+                          :properties {"limit" {:type "number"}}}
+             :strict false}]
+           (#'llm-providers.openai/->tools
+            [{:full-name "mcp__search_records"
+              :description "Search records"
+              :parameters {:type "object"
+                           :properties {"limit" {:type "number"}}}}]
+            false false)))))
 
 (deftest create-response-oauth-preserves-built-in-tools-test
   (testing "OAuth requests keep web_search and image_generation when capabilities are enabled"