diff --git a/packages/core/sdk/src/executor.test.ts b/packages/core/sdk/src/executor.test.ts
index 4e09e1162..0c1dd6a59 100644
--- a/packages/core/sdk/src/executor.test.ts
+++ b/packages/core/sdk/src/executor.test.ts
@@ -590,6 +590,129 @@ describe("createExecutor", () => {
     }),
   );
 
+  it.effect("tools.manifest syncs stale connection catalogs before reading", () =>
+    Effect.gen(function* () {
+      const staleIntegration = IntegrationSlug.make("stale-manifest");
+      const staleConnection = ConnectionName.make("main");
+      const staleAddress = (tool: string): ToolAddress =>
+        ToolAddress.make(`tools.${staleIntegration}.org.${staleConnection}.${tool}`);
+      const versionedPlugin = definePlugin(() => ({
+        id: "staleManifest" as const,
+        credentialProviders: [memoryProvider()],
+        storage: () => ({}),
+        resolveTools: ({ config }) => {
+          const version =
+            config && typeof config === "object" && "version" in config
+              ? String((config as { readonly version?: unknown }).version)
+              : "unknown";
+          return Effect.succeed({
+            tools: [
+              {
+                name: ToolName.make("inspect"),
+                description: `inspect ${version}`,
+              },
+            ],
+            definitions: {},
+            sourceRevision: version,
+          });
+        },
+        invokeTool: ({ toolRow }) => Effect.succeed({ ran: toolRow.name }),
+        extension: (ctx) => ({
+          seed: () =>
+            ctx.core.integrations.register({
+              slug: staleIntegration,
+              description: "Stale Manifest",
+              config: { version: "v1" },
+            }),
+          revise: (version: string) =>
+            ctx.core.integrations.update(staleIntegration, {
+              config: { version },
+            }),
+        }),
+      }))();
+
+      const executor = yield* makeTestExecutor({
+        plugins: [versionedPlugin] as const,
+      });
+      yield* executor.staleManifest.seed();
+      yield* executor.connections.create({
+        owner: "org",
+        name: staleConnection,
+        integration: staleIntegration,
+        template: TEMPLATE,
+        from: { provider: ProviderKey.make("memory"), id: ProviderItemId.make("v") },
+      });
+
+      const before = yield* executor.tools.manifest({
+        integration: staleIntegration,
+        includeBlocked: true,
+      });
+      expect(before).toHaveLength(1);
+      expect(before[0]).toMatchObject({
+        address: staleAddress("inspect"),
+        description: "inspect v1",
+        sourceRevision: "v1",
+      });
+
+      yield* executor.staleManifest.revise("v2");
+
+      const after = yield* executor.tools.manifest({
+        integration: staleIntegration,
+        includeBlocked: true,
+      });
+      expect(after).toHaveLength(1);
+      expect(after[0]).toMatchObject({
+        address: staleAddress("inspect"),
+        description: "inspect v2",
+        sourceRevision: "v2",
+      });
+    }),
+  );
+
+  it.effect("tools.manifest persists plugin-provided source revisions", () =>
+    Effect.gen(function* () {
+      const sourceRevision = "spec-hash-v1";
+      const sourcePlugin = definePlugin(() => ({
+        id: "sourceRevision" as const,
+        credentialProviders: [memoryProvider()],
+        storage: () => ({}),
+        resolveTools: () =>
+          Effect.succeed({
+            tools: [{ name: ToolName.make("inspect"), description: "inspect" }],
+            definitions: {},
+            sourceRevision,
+          }),
+        invokeTool: ({ toolRow }) => Effect.succeed({ ran: toolRow.name }),
+        extension: (ctx) => ({
+          seed: () =>
+            ctx.core.integrations.register({
+              slug: INTEG,
+              description: "Source",
+              config: { fallback: "would-be-hashed" },
+            }),
+        }),
+      }))();
+
+      const executor = yield* makeTestExecutor({
+        plugins: [sourcePlugin] as const,
+      });
+      yield* executor.sourceRevision.seed();
+      yield* executor.connections.create({
+        owner: "org",
+        name: CONN,
+        integration: INTEG,
+        template: TEMPLATE,
+        from: { provider: ProviderKey.make("memory"), id: ProviderItemId.make("v") },
+      });
+
+      const manifest = (yield* executor.tools.manifest({
+        integration: INTEG,
+        includeBlocked: true,
+      })).find((entry) => entry.name === "inspect");
+      expect(manifest?.sourceRevision).toBe(sourceRevision);
+    }),
+  );
+
   it.effect("execute dispatches a connection-produced tool to the owning plugin", () =>
     Effect.gen(function* () {
       const executor = yield* makeTestExecutor({
diff --git a/packages/core/sdk/src/executor.ts b/packages/core/sdk/src/executor.ts
index 3ab3757dc..923d0bea8 100644
--- a/packages/core/sdk/src/executor.ts
+++ b/packages/core/sdk/src/executor.ts
@@ -2724,7 +2724,9 @@ export const createExecutor = <const TPlugins extends readonly AnyPlugin[] = rea
           created_at: now,
         }));
         const definitionMap = new Map(Object.entries(result.definitions ?? {}));
-        const sourceRevision = yield* connectionToolSourceRevision(integrationRow, existingRow);
+        const sourceRevision =
+          result.sourceRevision ??
+          (yield* connectionToolSourceRevision(integrationRow, existingRow));
         const manifestRows = yield* Effect.forEach(
           result.tools,
           (tool: ToolDef) =>
@@ -3487,6 +3489,7 @@ export const createExecutor = <const TPlugins extends readonly AnyPlugin[] = rea
       filter?: ToolListFilter,
     ): Effect.Effect<readonly ToolSchemaManifest[], StorageFailure> =>
       Effect.gen(function* () {
+        yield* syncStaleConnectionTools;
         const rows = yield* core.findMany("tool_schema_manifest", {
           where: (b: AnyCb) =>
             b.and(
diff --git a/packages/core/sdk/src/plugin.ts b/packages/core/sdk/src/plugin.ts
index ea268209a..d375bf3e5 100644
--- a/packages/core/sdk/src/plugin.ts
+++ b/packages/core/sdk/src/plugin.ts
@@ -232,6 +232,11 @@ export interface ResolveToolsResult {
   readonly tools: readonly ToolDef[];
   /** Shared JSON-schema `$defs` reachable from the tools' `$ref`s. */
   readonly definitions?: Record<string, unknown>;
+  /** Optional plugin-owned source revision for the produced catalog. Spec-backed
+   *  plugins should provide their content hash; discovery-backed plugins can
+   *  provide a hash of the discovered manifest. The executor falls back to a
+   *  generic integration/connection revision when absent. */
+  readonly sourceRevision?: string;
 }
 
 // ---------------------------------------------------------------------------
diff --git a/packages/plugins/mcp/src/sdk/plugin.ts b/packages/plugins/mcp/src/sdk/plugin.ts
index 53d1bc584..bbaa59bf7 100644
--- a/packages/plugins/mcp/src/sdk/plugin.ts
+++ b/packages/plugins/mcp/src/sdk/plugin.ts
@@ -12,6 +12,7 @@ import {
   IntegrationSlug,
   mergeAuthTemplates,
   OAuthClientSlug,
+  sha256Hex,
   tool,
   ToolResult,
   type AuthMethodDescriptor,
@@ -957,7 +958,14 @@ export const mcpPlugin = definePlugin((options?: McpPluginOptions) => {
           : { ok: false as const, manifest: null };
 
         const entries = manifest.ok && manifest.manifest ? manifest.manifest.tools : [];
-        return { tools: entries.map(toToolDef) };
+        const sourceRevision =
+          manifest.ok && manifest.manifest
+            ? yield* sha256Hex(JSON.stringify(manifest.manifest))
+            : undefined;
+        return {
+          tools: entries.map(toToolDef),
+          ...(sourceRevision === undefined ? {} : { sourceRevision }),
+        };
       }).pipe(
         Effect.withSpan("mcp.plugin.resolve_tools", {
           attributes: { "mcp.connection.name": String(connection.name) },
diff --git a/packages/plugins/openapi/src/sdk/backing.ts b/packages/plugins/openapi/src/sdk/backing.ts
index 0018671e9..e7b2f8cc5 100644
--- a/packages/plugins/openapi/src/sdk/backing.ts
+++ b/packages/plugins/openapi/src/sdk/backing.ts
@@ -527,7 +527,11 @@ export const resolveOpenApiBackedTools = ({
         const definitions = Option.getOrNull(decodeDefsJson(defsJson));
         if (definitions != null) {
           const ops = yield* storage.listOperations(String(integration.slug));
-          return { tools: ops.map(toolDefFromStoredOperation), definitions };
+          return {
+            tools: ops.map(toolDefFromStoredOperation),
+            definitions,
+            sourceRevision: openApiConfig.specHash,
+          };
         }
       }
     }
@@ -540,6 +544,7 @@ export const resolveOpenApiBackedTools = ({
     return {
       tools: openApiToolDefsFromCompiled(compiled),
       definitions: compiled.hoistedDefs,
+      sourceRevision: openApiConfig.specHash,
     };
   });