feat: add tool descriptor planner

src/tools/protocol.ts

@@ -0,0 +1,22 @@
+import type { JsonObject, ToolPlanEntry } from "./types.js";
+
+export type ToolProtocolDescriptor = {
+  readonly name: string;
+  readonly description: string;
+  readonly inputSchema: JsonObject;
+};
+
+// Shared descriptor shape only. Model/provider adapters still own schema normalization.
+export function toToolProtocolDescriptor(entry: ToolPlanEntry): ToolProtocolDescriptor {
+  return {
+    name: entry.descriptor.name,
+    description: entry.descriptor.description,
+    inputSchema: entry.descriptor.inputSchema,
+  };
+}
+
+export function toToolProtocolDescriptors(
+  entries: readonly ToolPlanEntry[],
+): readonly ToolProtocolDescriptor[] {
+  return entries.map(toToolProtocolDescriptor);
+}