fix: mark enable_toolset and disable_toolset as non-destructive

src/meta/AGENTS.md

@@ -20,7 +20,7 @@ Registers meta-tools on MCP servers for runtime toolset management. Called by Se
 
 1. **`_meta` is a reserved toolset key** — If a catalog uses `"_meta"` as a toolset key, ToolRegistry will detect a name collision at registration time. Never use this key in the catalog.
 2. **Meta-tools registered via ToolRegistry** — Same collision detection path as user tools. Meta-tools appear in `toolRegistry.list()` and `toolRegistry.listByToolset()`.
-3. **`enable_toolset` / `disable_toolset` annotated with `destructiveHint: true`** — Visible to LLM clients via MCP tool annotations. Discovery tools (`list_*`, `describe_*`) use `readOnlyHint: true`.
+3. **`enable_toolset` / `disable_toolset` annotated with `destructiveHint: false, idempotentHint: true`** — They change which tools are exposed but destroy nothing, and repeating either call has no further effect on state. Visible to LLM clients via MCP tool annotations. Discovery tools (`list_*`, `describe_*`) use `readOnlyHint: true`.
 
 ## Anti-patterns
 

src/meta/registerMetaTools.ts

@@ -46,7 +46,7 @@ export function registerMetaTools(
       {
         description: "Enable a toolset by name",
         inputSchema: { name: z.string().describe("Toolset name") },
-        annotations: { destructiveHint: true, idempotentHint: true },
+        annotations: { destructiveHint: false, idempotentHint: true },
       },
       async (args: { name: string }) => {
         const result = await manager.enableToolset(args.name);
@@ -62,7 +62,7 @@ export function registerMetaTools(
       {
         description: "Disable a toolset by name (state only)",
         inputSchema: { name: z.string().describe("Toolset name") },
-        annotations: { destructiveHint: true, idempotentHint: true },
+        annotations: { destructiveHint: false, idempotentHint: true },
       },
       async (args: { name: string }) => {
         const result = await manager.disableToolset(args.name);

tests/metaTools.test.ts

@@ -330,4 +330,28 @@ describe("Meta-tools return formats", () => {
       expect(() => toolRegistry.add("enable_toolset")).toThrow(/collision/i);
     });
   });
+
+  describe("annotations", () => {
+    it("marks enable_toolset and disable_toolset as non-destructive and idempotent", () => {
+      const { tools } = createTestSetup();
+
+      for (const name of ["enable_toolset", "disable_toolset"]) {
+        expect(findTool(tools, name)?.annotations).toEqual({
+          destructiveHint: false,
+          idempotentHint: true,
+        });
+      }
+    });
+
+    it("marks discovery meta-tools as read-only", () => {
+      const { tools } = createTestSetup();
+
+      for (const name of ["list_toolsets", "describe_toolset", "list_tools"]) {
+        expect(findTool(tools, name)?.annotations).toEqual({
+          readOnlyHint: true,
+          idempotentHint: true,
+        });
+      }
+    });
+  });
 });