fix: parse tagged local-model tool calls

lib/agent/terminal-agent.mjs

@@ -91,6 +91,10 @@ export class TerminalAgent {
       const decision = parseDecision(response?.text);
       if (!decision) {
         const answer = String(response?.text || '').trim() || 'The agent returned no usable response.';
+        if (looksLikeProtocolPayload(answer)) {
+          working += '\n\nPROTOCOL ERROR: The previous tool syntax was malformed. Return the documented JSON tool_call or final object only.';
+          continue;
+        }
         this.lastTraceByChat.set(key, trace);
         return { answer, trace };
       }
@@ -272,6 +276,8 @@ Output exactly one JSON object without markdown:
 
 function parseDecision(text) {
   let value = String(text || '').trim().replace(/^```(?:json)?\s*/i, '').replace(/\s*```$/, '');
+  const tagged = parseTaggedToolCall(value);
+  if (tagged) return tagged;
   const match = value.match(/\{[\s\S]*\}/);
   if (match) value = match[0];
   try {
@@ -282,9 +288,53 @@ function parseDecision(text) {
   }
 }
 
+function parseTaggedToolCall(text) {
+  const callMatch = String(text || '').match(/<\|?tool_call\|?>\s*call:([a-z0-9_]+)\s*(\{[\s\S]*?\})\s*<(?:\/tool_call|tool_call\|)>/i);
+  if (callMatch) {
+    const argumentsValue = parseTaggedArguments(callMatch[2]);
+    if (argumentsValue) {
+      return {
+        type: 'tool_call',
+        tool: callMatch[1],
+        arguments: argumentsValue,
+        rationale: 'Model requested an allowlisted tool through tagged protocol.',
+      };
+    }
+  }
+
+  const jsonMatch = String(text || '').match(/<\|?tool_call\|?>\s*(\{[\s\S]*\})\s*<(?:\/tool_call|tool_call\|)>/i);
+  if (!jsonMatch) return null;
+  try {
+    const value = JSON.parse(jsonMatch[1]);
+    const tool = value.name || value.tool;
+    const args = value.arguments || value.parameters || {};
+    if (!/^[a-z0-9_]+$/i.test(String(tool || '')) || !args || Array.isArray(args) || typeof args !== 'object') return null;
+    return { type: 'tool_call', tool: String(tool), arguments: args, rationale: 'Model requested an allowlisted tool through tagged protocol.' };
+  } catch {
+    return null;
+  }
+}
+
+function parseTaggedArguments(value) {
+  const input = String(value || '').trim().slice(0, 4000);
+  try {
+    const parsed = JSON.parse(input);
+    return parsed && !Array.isArray(parsed) && typeof parsed === 'object' ? parsed : null;
+  } catch {
+    try {
+      const normalized = input.replace(/([{,]\s*)([a-z_][a-z0-9_]*)\s*:/gi, '$1"$2":');
+      const parsed = JSON.parse(normalized);
+      return parsed && !Array.isArray(parsed) && typeof parsed === 'object' ? parsed : null;
+    } catch {
+      return null;
+    }
+  }
+}
+
 function looksLikeProtocolPayload(text) {
   return /"?type"?\s*:\s*"?(?:tool_call|final)\b/i.test(text)
-    || /"?tool"?\s*:\s*"?[a-z0-9_]+/i.test(text);
+    || /"?tool"?\s*:\s*"?[a-z0-9_]+/i.test(text)
+    || /<\|?tool_call\|?>|<tool_call\|>|call:[a-z0-9_]+\s*\{/i.test(text);
 }
 
 function finalizationFailureMessage(input) {