diff --git a/extensions/memory-core/index.ts b/extensions/memory-core/index.ts
index 20d2b786ae5..c33ba5a1a5d 100644
--- a/extensions/memory-core/index.ts
+++ b/extensions/memory-core/index.ts
@@ -62,7 +62,7 @@ const MemorySearchSchema = {
   type: "object",
   properties: {
     query: { type: "string" },
-    maxResults: { type: "number" },
+    maxResults: { type: "integer", minimum: 1 },
     minScore: { type: "number" },
     corpus: { type: "string", enum: ["memory", "wiki", "all", "sessions"] },
   },
diff --git a/extensions/memory-core/src/tools.shared.ts b/extensions/memory-core/src/tools.shared.ts
index 79a0832b9b5..1b5e5db2134 100644
--- a/extensions/memory-core/src/tools.shared.ts
+++ b/extensions/memory-core/src/tools.shared.ts
@@ -30,7 +30,7 @@ export async function loadMemoryToolRuntime(): Promise<MemoryToolRuntime> {
 
 export const MemorySearchSchema = Type.Object({
   query: Type.String(),
-  maxResults: Type.Optional(Type.Number()),
+  maxResults: Type.Optional(Type.Integer({ minimum: 1 })),
   minScore: Type.Optional(Type.Number()),
   corpus: Type.Optional(stringEnum(["memory", "wiki", "all", "sessions"])),
 });
diff --git a/extensions/memory-core/src/tools.test.ts b/extensions/memory-core/src/tools.test.ts
index 4a2e4ad41a7..6a819062ab9 100644
--- a/extensions/memory-core/src/tools.test.ts
+++ b/extensions/memory-core/src/tools.test.ts
@@ -58,6 +58,19 @@ describe("memory_search unavailable payloads", () => {
     resetMemoryToolMockState({ searchImpl: async () => [] });
   });
 
+  it("rejects fractional maxResults before searching", async () => {
+    const tool = createMemorySearchToolOrThrow();
+
+    await expect(
+      tool.execute("fractional-max-results", {
+        query: "hello",
+        maxResults: 1.5,
+      }),
+    ).rejects.toThrow("maxResults must be a positive integer");
+
+    expect(getMemorySearchManagerMockCalls()).toBe(0);
+  });
+
   it("returns explicit unavailable metadata for quota failures", async () => {
     setMemorySearchImpl(async () => {
       throw new Error("openai embeddings failed: 429 insufficient_quota");
diff --git a/extensions/memory-core/src/tools.ts b/extensions/memory-core/src/tools.ts
index fbae68dd9f2..04635a08b9e 100644
--- a/extensions/memory-core/src/tools.ts
+++ b/extensions/memory-core/src/tools.ts
@@ -256,7 +256,7 @@ export function createMemorySearchTool(options: {
       async (_toolCallId, params) => {
         const rawParams = asToolParamsRecord(params);
         const query = readStringParam(rawParams, "query", { required: true });
-        const maxResults = readNumberParam(rawParams, "maxResults");
+        const maxResults = readPositiveIntegerParam(rawParams, "maxResults");
         const minScore = readNumberParam(rawParams, "minScore");
         const requestedCorpus = readStringParam(rawParams, "corpus") as
           | "memory"