diff --git a/apps/server/src/mcp/WorktreeMcpService.test.ts b/apps/server/src/mcp/WorktreeMcpService.test.ts
index c6a00aabcb0cc..3be8705cc0bb0 100644
--- a/apps/server/src/mcp/WorktreeMcpService.test.ts
+++ b/apps/server/src/mcp/WorktreeMcpService.test.ts
@@ -350,9 +350,7 @@ const expectTypedFailure = (exit: Exit.Exit<unknown, unknown>, expected: object)
 
 // Resolve once so calls share the in-flight guard.
 const resolveService = (harness: ReturnType<typeof makeHarness>) =>
-  Effect.gen(function* () {
-    return yield* WorktreeMcpService.WorktreeMcpService;
-  }).pipe(Effect.provide(harness.layer));
+  WorktreeMcpService.WorktreeMcpService.pipe(Effect.provide(harness.layer));
 
 const runHandoff = (
   harness: ReturnType<typeof makeHarness>,
diff --git a/packages/provider-acp/src/server/adapter.ts b/packages/provider-acp/src/server/adapter.ts
index bf39035f1f415..5eb12a80d9df9 100644
--- a/packages/provider-acp/src/server/adapter.ts
+++ b/packages/provider-acp/src/server/adapter.ts
@@ -5339,12 +5339,10 @@ export const makeAcpAdapterV2 = Effect.fn("makeAcpAdapterV2")(function* (
                   Effect.ensuring(
                     runRuntimeCallbackAtGeneration(
                       generation,
-                      Effect.gen(function* () {
-                        yield* Ref.update(pendingRuntimeRequests, (current) => {
-                          const updated = new Map(current);
-                          updated.delete(String(requestId));
-                          return updated;
-                        });
+                      Ref.update(pendingRuntimeRequests, (current) => {
+                        const updated = new Map(current);
+                        updated.delete(String(requestId));
+                        return updated;
                       }),
                     ).pipe(Effect.asVoid),
                   ),
@@ -6032,12 +6030,10 @@ export const makeAcpAdapterV2 = Effect.fn("makeAcpAdapterV2")(function* (
                 Effect.ensuring(
                   runRuntimeCallbackAtGeneration(
                     handlerGeneration,
-                    Effect.gen(function* () {
-                      yield* Ref.update(pendingRuntimeRequests, (current) => {
-                        const updated = new Map(current);
-                        updated.delete(String(requestId));
-                        return updated;
-                      });
+                    Ref.update(pendingRuntimeRequests, (current) => {
+                      const updated = new Map(current);
+                      updated.delete(String(requestId));
+                      return updated;
                     }),
                   ).pipe(Effect.asVoid),
                 ),
diff --git a/packages/provider-cursor/src/server/usageLimits.test.ts b/packages/provider-cursor/src/server/usageLimits.test.ts
index ce8a2cbc27cf3..1b4cadf88ae3f 100644
--- a/packages/provider-cursor/src/server/usageLimits.test.ts
+++ b/packages/provider-cursor/src/server/usageLimits.test.ts
@@ -71,49 +71,47 @@ describe("Cursor usage limits", () => {
   });
 
   it.effect("reads the instance's credentials and endpoint even when usage enabled is false", () =>
-    Effect.gen(function* () {
-      yield* withNodeServices(
-        Effect.gen(function* () {
-          const fs = yield* FileSystem.FileSystem;
-          const path = yield* Path.Path;
-          const directory = yield* fs.makeTempDirectoryScoped();
-          yield* fs.makeDirectory(path.join(directory, "cursor"));
-          yield* fs.writeFileString(
-            path.join(directory, "cursor", "auth.json"),
-            '{"accessToken":"instance-token"}',
+    withNodeServices(
+      Effect.gen(function* () {
+        const fs = yield* FileSystem.FileSystem;
+        const path = yield* Path.Path;
+        const directory = yield* fs.makeTempDirectoryScoped();
+        yield* fs.makeDirectory(path.join(directory, "cursor"));
+        yield* fs.writeFileString(
+          path.join(directory, "cursor", "auth.json"),
+          '{"accessToken":"instance-token"}',
+        );
+        const client = HttpClient.make((request) => {
+          expect(request.url).toBe(
+            "https://cursor.example/aiserver.v1.DashboardService/GetCurrentPeriodUsage",
           );
-          const client = HttpClient.make((request) => {
-            expect(request.url).toBe(
-              "https://cursor.example/aiserver.v1.DashboardService/GetCurrentPeriodUsage",
-            );
-            expect(request.method).toBe("POST");
-            expect(request.headers.authorization).toBe("Bearer instance-token");
-            expect(request.headers["connect-protocol-version"]).toBe("1");
-            return Effect.succeed(
-              HttpClientResponse.fromWeb(
-                request,
-                Response.json({ enabled: false, planUsage: { totalPercentUsed: 42 } }),
-              ),
-            );
-          });
-          yield* fs.makeDirectory(path.join(directory, ".cursor"));
-          yield* fs.writeFileString(
-            path.join(directory, ".cursor", "auth.json"),
-            '{"accessToken":"instance-token"}',
+          expect(request.method).toBe("POST");
+          expect(request.headers.authorization).toBe("Bearer instance-token");
+          expect(request.headers["connect-protocol-version"]).toBe("1");
+          return Effect.succeed(
+            HttpClientResponse.fromWeb(
+              request,
+              Response.json({ enabled: false, planUsage: { totalPercentUsed: 42 } }),
+            ),
           );
-          for (const platform of ["linux", "darwin"] as const) {
-            const limits = yield* readCursorUsageLimits(
-              { apiEndpoint: "https://cursor.example/" },
-              { XDG_CONFIG_HOME: directory, HOME: directory, AGENT_CLI_CREDENTIAL_STORE: "file" },
-            ).pipe(
-              Effect.provideService(HostProcess.Platform, platform),
-              Effect.provideService(HttpClient.HttpClient, client),
-            );
-            expect(limits.windows[0]?.usedPercent).toBe(42);
-          }
-        }).pipe(Effect.scoped),
-      );
-    }),
+        });
+        yield* fs.makeDirectory(path.join(directory, ".cursor"));
+        yield* fs.writeFileString(
+          path.join(directory, ".cursor", "auth.json"),
+          '{"accessToken":"instance-token"}',
+        );
+        for (const platform of ["linux", "darwin"] as const) {
+          const limits = yield* readCursorUsageLimits(
+            { apiEndpoint: "https://cursor.example/" },
+            { XDG_CONFIG_HOME: directory, HOME: directory, AGENT_CLI_CREDENTIAL_STORE: "file" },
+          ).pipe(
+            Effect.provideService(HostProcess.Platform, platform),
+            Effect.provideService(HttpClient.HttpClient, client),
+          );
+          expect(limits.windows[0]?.usedPercent).toBe(42);
+        }
+      }).pipe(Effect.scoped),
+    ),
   );
 
   it.effect(
diff --git a/tsconfig.base.json b/tsconfig.base.json
index bd872178ff210..d1aca92648b50 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -24,6 +24,7 @@
         "namespaceImportPackages": ["@effect/platform-node", "effect"],
         "effectFn": ["span", "inferred-span", "suggested-span"],
         "diagnosticSeverity": {
+          "unnecessaryEffectGen": "error",
           "allOfMapToForEach": "error",
           "catchToOrElseSucceed": "error",
           "unnecessaryFailYieldableError": "error",