Revert "fix: flatten remaining anyOf/oneOf in Gemini schema cleaning"

This reverts commit 06b961b037.

src/agents/pi-tools.schema.ts

@@ -62,7 +62,10 @@ function mergePropertySchemas(existing: unknown, incoming: unknown): unknown {
   return existing;
 }
 
-export function normalizeToolParameters(tool: AnyAgentTool): AnyAgentTool {
+export function normalizeToolParameters(
+  tool: AnyAgentTool,
+  options?: { modelProvider?: string },
+): AnyAgentTool {
   const schema =
     tool.parameters && typeof tool.parameters === "object"
       ? (tool.parameters as Record<string, unknown>)
@@ -75,15 +78,23 @@ export function normalizeToolParameters(tool: AnyAgentTool): AnyAgentTool {
   // - Gemini rejects several JSON Schema keywords, so we scrub those.
   // - OpenAI rejects function tool schemas unless the *top-level* is `type: "object"`.
   //   (TypeBox root unions compile to `{ anyOf: [...] }` without `type`).
+  // - Anthropic (google-antigravity) expects full JSON Schema draft 2020-12 compliance.
   //
   // Normalize once here so callers can always pass `tools` through unchanged.
 
+  const isGeminiProvider =
+    options?.modelProvider?.toLowerCase().includes("google") ||
+    options?.modelProvider?.toLowerCase().includes("gemini");
+  const isAnthropicProvider =
+    options?.modelProvider?.toLowerCase().includes("anthropic") ||
+    options?.modelProvider?.toLowerCase().includes("google-antigravity");
+
   // If schema already has type + properties (no top-level anyOf to merge),
-  // still clean it for Gemini compatibility
+  // clean it for Gemini compatibility (but only if using Gemini, not Anthropic)
   if ("type" in schema && "properties" in schema && !Array.isArray(schema.anyOf)) {
     return {
       ...tool,
-      parameters: cleanSchemaForGemini(schema),
+      parameters: isGeminiProvider && !isAnthropicProvider ? cleanSchemaForGemini(schema) : schema,
     };
   }
 
@@ -95,9 +106,13 @@ export function normalizeToolParameters(tool: AnyAgentTool): AnyAgentTool {
     !Array.isArray(schema.anyOf) &&
     !Array.isArray(schema.oneOf)
   ) {
+    const schemaWithType = { ...schema, type: "object" };
     return {
       ...tool,
-      parameters: cleanSchemaForGemini({ ...schema, type: "object" }),
+      parameters:
+        isGeminiProvider && !isAnthropicProvider
+          ? cleanSchemaForGemini(schemaWithType)
+          : schemaWithType,
     };
   }
 
@@ -154,26 +169,34 @@ export function normalizeToolParameters(tool: AnyAgentTool): AnyAgentTool {
         : undefined;
 
   const nextSchema: Record<string, unknown> = { ...schema };
+  const flattenedSchema = {
+    type: "object",
+    ...(typeof nextSchema.title === "string" ? { title: nextSchema.title } : {}),
+    ...(typeof nextSchema.description === "string" ? { description: nextSchema.description } : {}),
+    properties:
+      Object.keys(mergedProperties).length > 0 ? mergedProperties : (schema.properties ?? {}),
+    ...(mergedRequired && mergedRequired.length > 0 ? { required: mergedRequired } : {}),
+    additionalProperties: "additionalProperties" in schema ? schema.additionalProperties : true,
+  };
+
   return {
     ...tool,
     // Flatten union schemas into a single object schema:
     // - Gemini doesn't allow top-level `type` together with `anyOf`.
     // - OpenAI rejects schemas without top-level `type: "object"`.
+    // - Anthropic accepts proper JSON Schema with constraints.
     // Merging properties preserves useful enums like `action` while keeping schemas portable.
-    parameters: cleanSchemaForGemini({
-      type: "object",
-      ...(typeof nextSchema.title === "string" ? { title: nextSchema.title } : {}),
-      ...(typeof nextSchema.description === "string"
-        ? { description: nextSchema.description }
-        : {}),
-      properties:
-        Object.keys(mergedProperties).length > 0 ? mergedProperties : (schema.properties ?? {}),
-      ...(mergedRequired && mergedRequired.length > 0 ? { required: mergedRequired } : {}),
-      additionalProperties: "additionalProperties" in schema ? schema.additionalProperties : true,
-    }),
+    parameters:
+      isGeminiProvider && !isAnthropicProvider
+        ? cleanSchemaForGemini(flattenedSchema)
+        : flattenedSchema,
   };
 }
 
+/**
+ * @deprecated Use normalizeToolParameters with modelProvider instead.
+ * This function should only be used for Gemini providers.
+ */
 export function cleanToolSchemaForGemini(schema: Record<string, unknown>): unknown {
   return cleanSchemaForGemini(schema);
 }