diff --git a/src/ports/writable-grant-store.ts b/src/ports/writable-grant-store.ts
index 5d572bb..cefbbcf 100644
--- a/src/ports/writable-grant-store.ts
+++ b/src/ports/writable-grant-store.ts
@@ -32,15 +32,30 @@ export function createInMemoryWritableGrantStore(
   initial: GrantRule[] = [],
 ): WritableGrantStore & { grants: GrantRule[] } {
   const grants = [...initial];
-  return {
+  function collect(principalId: string) {
+    const now = new Date();
+    return grants.filter((g) => {
+      if (g.principalId !== principalId) return false;
+      if (g.expiresAt !== null && g.expiresAt <= now) return false;
+      return true;
+    });
+  }
+  // Bound to a const rather than returned as a fresh object literal: some
+  // `@intx/authz` versions require `collectGrantsInChain` on `GrantStore`
+  // (an ancestor-chain walk) that this package's own pinned version
+  // predates. Routing through a named variable gets normal structural
+  // assignment for the function's declared return type instead of
+  // TypeScript's excess-property check on literals, so this satisfies
+  // either shape — tenantId (and thus the ancestor chain) is a no-op here
+  // regardless, matching `createInMemoryGrantStore`'s own tenant-scoped
+  // fixture semantics.
+  const store = {
     grants,
     async collectGrants(principalId: string, _tenantId?: string) {
-      const now = new Date();
-      return grants.filter((g) => {
-        if (g.principalId !== principalId) return false;
-        if (g.expiresAt !== null && g.expiresAt <= now) return false;
-        return true;
-      });
+      return collect(principalId);
+    },
+    async collectGrantsInChain(principalId: string, _tenantId?: string) {
+      return collect(principalId);
     },
     async putGrant(grant: GrantRule) {
       const idx = grants.findIndex((g) => g.id === grant.id);
@@ -48,4 +63,5 @@ export function createInMemoryWritableGrantStore(
       else grants.push(grant);
     },
   };
+  return store;
 }
diff --git a/src/tools/install.ts b/src/tools/install.ts
index 688dd62..a098739 100644
--- a/src/tools/install.ts
+++ b/src/tools/install.ts
@@ -37,10 +37,19 @@ export function defineMemoryHttpTool(opts: {
     signal: AbortSignal | undefined,
   ) => Promise<string>;
 }) {
-  return defineTool<MemoryInstallEnv>({
+  // Bound to a const rather than passed as a fresh object literal: some
+  // `@intx/agent` versions add a static `definitions` field to defineTool's
+  // options (so callers can enumerate tool names without instantiating the
+  // factory) that this package's own pinned version predates. Routing
+  // through a named variable gets normal structural (duck-typed) parameter
+  // assignment instead of TypeScript's excess-property check on literals,
+  // so this call type-checks against either shape — the extra field is
+  // simply unused by an older defineTool at runtime.
+  const toolOpts = {
     id: opts.id,
     requires: MEMORY_TOOL_ENV_KEYS,
-    factory(env) {
+    definitions: [{ name: opts.name }],
+    factory(env: MemoryInstallEnv) {
       const client = createMemoryHttpClient(readMemoryToolEnv(env));
       const runner = createToolRunner([
         stringTool({
@@ -55,8 +64,9 @@ export function defineMemoryHttpTool(opts: {
       ]);
       return {
         definitions: runner.definitions,
-        run: (call, signal) => runner.run(call, signal),
+        run: runner.run.bind(runner),
       };
     },
-  });
+  };
+  return defineTool<MemoryInstallEnv>(toolOpts);
 }