Merge pull request #187 from CJackHwang/codex/investigate-unrecognized-issue-in-ds2api

fix: use schema-correct exec parameter examples in tool prompt

internal/adapter/openai/tool_sieve_core.go

@@ -183,7 +183,7 @@ func findToolSegmentStart(s string) int {
 		return -1
 	}
 	lower := strings.ToLower(s)
-	keywords := []string{"tool_calls", "\"function\"", "function.name:", "functioncall", "\"tool_use\""}
+	keywords := []string{"tool_calls", "\"function\"", "function.name:", "\"tool_use\""}
 	bestKeyIdx := -1
 	for _, kw := range keywords {
 		idx := strings.Index(lower, kw)
@@ -191,6 +191,9 @@ func findToolSegmentStart(s string) int {
 			bestKeyIdx = idx
 		}
 	}
+	if fnKeyIdx := findQuotedFunctionCallKeyStart(s); fnKeyIdx >= 0 && (bestKeyIdx < 0 || fnKeyIdx < bestKeyIdx) {
+		bestKeyIdx = fnKeyIdx
+	}
 	// Also detect XML tool call tags.
 	for _, tag := range xmlToolTagsToDetect {
 		idx := strings.Index(lower, tag)
@@ -240,13 +243,16 @@ func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix
 
 	lower := strings.ToLower(captured)
 	keyIdx := -1
-	keywords := []string{"tool_calls", "\"function\"", "function.name:", "functioncall", "\"tool_use\""}
+	keywords := []string{"tool_calls", "\"function\"", "function.name:", "\"tool_use\""}
 	for _, kw := range keywords {
 		idx := strings.Index(lower, kw)
 		if idx >= 0 && (keyIdx < 0 || idx < keyIdx) {
 			keyIdx = idx
 		}
 	}
+	if fnKeyIdx := findQuotedFunctionCallKeyStart(captured); fnKeyIdx >= 0 && (keyIdx < 0 || fnKeyIdx < keyIdx) {
+		keyIdx = fnKeyIdx
+	}
 
 	if keyIdx < 0 {
 		return "", nil, "", false

internal/adapter/openai/tool_sieve_functioncall.go

@@ -0,0 +1,100 @@
+package openai
+
+import "strings"
+
+func findQuotedFunctionCallKeyStart(s string) int {
+	lower := strings.ToLower(s)
+	quotedIdx := findFunctionCallKeyStart(lower, `"functioncall"`)
+	bareIdx := findFunctionCallKeyStart(lower, "functioncall")
+
+	// Prefer the quoted JSON key whenever we have a structural match.
+	// Bare-key detection is only for loose payloads where the quoted form
+	// is absent.
+	if quotedIdx >= 0 {
+		return quotedIdx
+	}
+	return bareIdx
+}
+
+func findFunctionCallKeyStart(lower, key string) int {
+	for from := 0; from < len(lower); {
+		rel := strings.Index(lower[from:], key)
+		if rel < 0 {
+			return -1
+		}
+		idx := from + rel
+		if isInsideJSONString(lower, idx) {
+			from = idx + 1
+			continue
+		}
+		if !hasJSONObjectContextPrefix(lower[:idx]) {
+			from = idx + 1
+			continue
+		}
+		if !hasJSONKeyBoundary(lower, idx, len(key)) {
+			from = idx + 1
+			continue
+		}
+		j := idx + len(key)
+		for j < len(lower) && (lower[j] == ' ' || lower[j] == '\t' || lower[j] == '\r' || lower[j] == '\n') {
+			j++
+		}
+		if j < len(lower) && lower[j] == ':' {
+			k := j + 1
+			for k < len(lower) && (lower[k] == ' ' || lower[k] == '\t' || lower[k] == '\r' || lower[k] == '\n') {
+				k++
+			}
+			if k < len(lower) && lower[k] != '{' {
+				from = idx + 1
+				continue
+			}
+			return idx
+		}
+		from = idx + 1
+	}
+	return -1
+}
+
+func isInsideJSONString(s string, idx int) bool {
+	inString := false
+	escaped := false
+	for i := 0; i < idx; i++ {
+		c := s[i]
+		if escaped {
+			escaped = false
+			continue
+		}
+		if c == '\\' && inString {
+			escaped = true
+			continue
+		}
+		if c == '"' {
+			inString = !inString
+		}
+	}
+	return inString
+}
+
+func hasJSONObjectContextPrefix(prefix string) bool {
+	return strings.LastIndex(prefix, "{") >= 0
+}
+
+func hasJSONKeyBoundary(s string, idx, keyLen int) bool {
+	if idx > 0 {
+		prev := s[idx-1]
+		if isLowerAlphaNumeric(prev) {
+			return false
+		}
+	}
+	if end := idx + keyLen; end < len(s) {
+		next := s[end]
+		if isLowerAlphaNumeric(next) {
+			return false
+		}
+	}
+	return true
+}
+
+func isLowerAlphaNumeric(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= '0' && b <= '9') || b == '_'
+}

internal/adapter/openai/tool_sieve_functioncall_test.go

@@ -0,0 +1,23 @@
+package openai
+
+import "testing"
+
+func TestFindQuotedFunctionCallKeyStart_PrefersEarlierBareKey(t *testing.T) {
+	input := `{functionCall:{"name":"a","arguments":"{}"},"message":"literal text: \"functionCall\": not a key"}`
+
+	got := findQuotedFunctionCallKeyStart(input)
+	want := 1
+	if got != want {
+		t.Fatalf("findQuotedFunctionCallKeyStart() = %d, want %d", got, want)
+	}
+}
+
+func TestFindQuotedFunctionCallKeyStart_PrefersEarlierQuotedKey(t *testing.T) {
+	input := `{"functionCall":{"name":"a","arguments":"{}"},"note":"functionCall appears in prose"}`
+
+	got := findQuotedFunctionCallKeyStart(input)
+	want := 1
+	if got != want {
+		t.Fatalf("findQuotedFunctionCallKeyStart() = %d, want %d", got, want)
+	}
+}

internal/adapter/openai/tool_sieve_xml_test.go

@@ -120,6 +120,60 @@ func TestFindToolSegmentStartDetectsXMLToolCalls(t *testing.T) {
 	}
 }
 
+func TestFindToolSegmentStartIgnoresFunctionCallProse(t *testing.T) {
+	input := "Please explain the functionCall API field and how clients should parse it."
+	if got := findToolSegmentStart(input); got != -1 {
+		t.Fatalf("expected no tool segment start for prose, got %d", got)
+	}
+}
+
+func TestFindToolSegmentStartDetectsQuotedFunctionCallKey(t *testing.T) {
+	input := `prefix {"functionCall": {"name":"search_web","args":{"query":"x"}}}`
+	want := strings.Index(input, "{")
+	if got := findToolSegmentStart(input); got != want {
+		t.Fatalf("expected JSON object start %d, got %d", want, got)
+	}
+}
+
+func TestFindToolSegmentStartDetectsLooseFunctionCallKey(t *testing.T) {
+	input := `prefix {functionCall: {"name":"search_web","args":{"query":"x"}}}`
+	want := strings.Index(input, "{")
+	if got := findToolSegmentStart(input); got != want {
+		t.Fatalf("expected JSON object start %d, got %d", want, got)
+	}
+}
+
+func TestFindToolSegmentStartPrefersQuotedFunctionCallOverEarlierBareProse(t *testing.T) {
+	input := `prefix {note} functionCall: docs hint {"functionCall":{"name":"search_web","args":{"query":"x"}}}`
+	want := strings.Index(input, `{"functionCall"`)
+	if got := findToolSegmentStart(input); got != want {
+		t.Fatalf("expected quoted functionCall JSON start %d, got %d", want, got)
+	}
+}
+
+func TestFindToolSegmentStartIgnoresLooseFunctionCallProse(t *testing.T) {
+	input := "Please explain why functionCall: is used in documentation examples."
+	if got := findToolSegmentStart(input); got != -1 {
+		t.Fatalf("expected no tool segment start for prose, got %d", got)
+	}
+}
+
+func TestProcessToolSieveDoesNotBufferFunctionCallProse(t *testing.T) {
+	var state toolStreamSieveState
+	chunk := "Please explain the functionCall API field and keep streaming this sentence."
+	events := processToolSieveChunk(&state, chunk, []string{"search_web"})
+	var text string
+	for _, evt := range events {
+		text += evt.Content
+		if len(evt.ToolCalls) > 0 {
+			t.Fatalf("expected no tool calls for prose, got %#v", evt.ToolCalls)
+		}
+	}
+	if text != chunk {
+		t.Fatalf("expected prose to pass through immediately, got %q", text)
+	}
+}
+
 func TestProcessToolSieveDetectsGeminiFunctionCallPayload(t *testing.T) {
 	var state toolStreamSieveState
 	events := processToolSieveChunk(&state, `{"functionCall":{"name":"search_web","args":{"query":"latest"}}}`, []string{"search_web"})

internal/util/tool_prompt.go

@@ -1,5 +1,7 @@
 package util
 
+import "strings"
+
 // BuildToolCallInstructions generates the unified tool-calling instruction block
 // used by all adapters (OpenAI, Claude, Gemini). It uses attention-optimized
 // structure: rules → negative examples → positive examples → anchor.
@@ -19,7 +21,7 @@ func BuildToolCallInstructions(toolNames []string) string {
 			ex1 = n
 			used["ex1"] = true
 		// Write/execute-type tools
-		case !used["ex2"] && matchAny(n, "write_to_file", "apply_diff", "execute_command", "Write", "Edit", "MultiEdit", "Bash"):
+		case !used["ex2"] && matchAny(n, "write_to_file", "apply_diff", "execute_command", "exec_command", "Write", "Edit", "MultiEdit", "Bash"):
 			ex2 = n
 			used["ex2"] = true
 		// Interactive/meta tools
@@ -28,6 +30,9 @@ func BuildToolCallInstructions(toolNames []string) string {
 			used["ex3"] = true
 		}
 	}
+	ex1Params := exampleReadParams(ex1)
+	ex2Params := exampleWriteOrExecParams(ex2)
+	ex3Params := exampleInteractiveParams(ex3)
 
 	return `TOOL CALL FORMAT — FOLLOW EXACTLY:
 
@@ -47,6 +52,7 @@ RULES:
 4) Do NOT wrap the XML in markdown code fences (no triple backticks).
 5) After receiving a tool result, use it directly. Only call another tool if the result is insufficient.
 6) If you want to say something AND call a tool, output text first, then the XML block on its own.
+7) Parameters MUST use the exact field names from the selected tool schema.
 
 ❌ WRONG — Do NOT do these:
 Wrong 1 — mixed text and XML:
@@ -62,7 +68,7 @@ Example A — Single tool:
 <tool_calls>
   <tool_call>
     <tool_name>` + ex1 + `</tool_name>
-    <parameters>{"path":"src/main.go"}</parameters>
+    <parameters>` + ex1Params + `</parameters>
   </tool_call>
 </tool_calls>
 
@@ -70,11 +76,11 @@ Example B — Two tools in parallel:
 <tool_calls>
   <tool_call>
     <tool_name>` + ex1 + `</tool_name>
-    <parameters>{"path":"config.json"}</parameters>
+    <parameters>` + ex1Params + `</parameters>
   </tool_call>
   <tool_call>
     <tool_name>` + ex2 + `</tool_name>
-    <parameters>{"path":"output.txt","content":"Hello world"}</parameters>
+    <parameters>` + ex2Params + `</parameters>
   </tool_call>
 </tool_calls>
 
@@ -82,7 +88,7 @@ Example C — Tool with complex nested JSON parameters:
 <tool_calls>
   <tool_call>
     <tool_name>` + ex3 + `</tool_name>
-    <parameters>{"question":"Which approach do you prefer?","follow_up":[{"text":"Option A"},{"text":"Option B"}]}</parameters>
+    <parameters>` + ex3Params + `</parameters>
   </tool_call>
 </tool_calls>
 
@@ -97,3 +103,38 @@ func matchAny(name string, candidates ...string) bool {
 	}
 	return false
 }
+
+func exampleReadParams(name string) string {
+	switch strings.TrimSpace(name) {
+	case "Read":
+		return `{"file_path":"README.md"}`
+	case "Glob":
+		return `{"pattern":"**/*.go","path":"."}`
+	default:
+		return `{"path":"src/main.go"}`
+	}
+}
+
+func exampleWriteOrExecParams(name string) string {
+	switch strings.TrimSpace(name) {
+	case "Bash", "execute_command":
+		return `{"command":"pwd"}`
+	case "exec_command":
+		return `{"cmd":"pwd"}`
+	case "Edit":
+		return `{"file_path":"README.md","old_string":"foo","new_string":"bar"}`
+	case "MultiEdit":
+		return `{"file_path":"README.md","edits":[{"old_string":"foo","new_string":"bar"}]}`
+	default:
+		return `{"path":"output.txt","content":"Hello world"}`
+	}
+}
+
+func exampleInteractiveParams(name string) string {
+	switch strings.TrimSpace(name) {
+	case "Task":
+		return `{"description":"Investigate flaky tests","prompt":"Run targeted tests and summarize failures"}`
+	default:
+		return `{"question":"Which approach do you prefer?","follow_up":[{"text":"Option A"},{"text":"Option B"}]}`
+	}
+}

internal/util/tool_prompt_test.go

@@ -0,0 +1,26 @@
+package util
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestBuildToolCallInstructions_ExecCommandUsesCmdExample(t *testing.T) {
+	out := BuildToolCallInstructions([]string{"exec_command"})
+	if !strings.Contains(out, `<tool_name>exec_command</tool_name>`) {
+		t.Fatalf("expected exec_command in examples, got: %s", out)
+	}
+	if !strings.Contains(out, `<parameters>{"cmd":"pwd"}</parameters>`) {
+		t.Fatalf("expected cmd parameter example for exec_command, got: %s", out)
+	}
+}
+
+func TestBuildToolCallInstructions_ExecuteCommandUsesCommandExample(t *testing.T) {
+	out := BuildToolCallInstructions([]string{"execute_command"})
+	if !strings.Contains(out, `<tool_name>execute_command</tool_name>`) {
+		t.Fatalf("expected execute_command in examples, got: %s", out)
+	}
+	if !strings.Contains(out, `<parameters>{"command":"pwd"}</parameters>`) {
+		t.Fatalf("expected command parameter example for execute_command, got: %s", out)
+	}
+}