feat: align Go/Node DSML tool-call parsing drift tolerance and update API docs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/promptcompat/prompt_build_test.go

@@ -113,6 +113,9 @@ func TestBuildOpenAIPromptWithToolInstructionsOnlyOmitsSchemas(t *testing.T) {
 	if strings.Contains(finalPrompt, "You have access to these tools") || strings.Contains(finalPrompt, "Description: search docs") || strings.Contains(finalPrompt, "Parameters:") {
 		t.Fatalf("tool descriptions should be externalized, got: %q", finalPrompt)
 	}
+	if !strings.Contains(finalPrompt, "Treat DS2API_TOOLS.txt as the authoritative list of callable tools and schemas") {
+		t.Fatalf("expected instructions-only prompt to point model at tools file, got: %q", finalPrompt)
+	}
 	if !strings.Contains(finalPrompt, "TOOL CALL FORMAT") || !strings.Contains(finalPrompt, "Remember: The ONLY valid way to use tools") {
 		t.Fatalf("expected tool format instructions to remain in live prompt, got: %q", finalPrompt)
 	}

internal/promptcompat/standard_request.go

@@ -11,6 +11,8 @@ type StandardRequest struct {
 	HistoryText             string
 	PromptTokenText         string
 	CurrentInputFileApplied bool
+	CurrentInputFileID      string
+	CurrentToolsFileID      string
 	ToolsRaw                any
 	FinalPrompt             string
 	ToolNames               []string

internal/promptcompat/tool_prompt.go

@@ -39,6 +39,8 @@ func injectToolPromptWithDescriptions(messages []map[string]any, tools []any, po
 	toolPrompt := parts.Instructions
 	if includeDescriptions && parts.Descriptions != "" {
 		toolPrompt = parts.Descriptions + "\n\n" + toolPrompt
+	} else if !includeDescriptions && parts.Descriptions != "" {
+		toolPrompt = "Available tool descriptions and parameter schemas are attached in DS2API_TOOLS.txt. Treat DS2API_TOOLS.txt as the authoritative list of callable tools and schemas; use only tools and parameters listed there.\n\n" + toolPrompt
 	}
 
 	for i := range messages {