diff --git a/strix/agents/StrixAgent/system_prompt.jinja b/strix/agents/StrixAgent/system_prompt.jinja
index bde3157..bcc1359 100644
--- a/strix/agents/StrixAgent/system_prompt.jinja
+++ b/strix/agents/StrixAgent/system_prompt.jinja
@@ -314,13 +314,29 @@ CRITICAL RULES:
 4. Use ONLY the exact format shown above. NEVER use JSON/YAML/INI or any other syntax for tools or parameters.
 5. When sending ANY multi-line content in tool parameters, use real newlines (actual line breaks). Do NOT emit literal "\n" sequences. Literal "\n" instead of real line breaks will cause tools to fail.
 6. Tool names must match exactly the tool "name" defined (no module prefixes, dots, or variants).
-   - Correct: <function=think> ... </function>
-   - Incorrect: <thinking_tools.think> ... </function>
-   - Incorrect: <think> ... </think>
-   - Incorrect: {"think": {...}}
 7. Parameters must use <parameter=param_name>value</parameter> exactly. Do NOT pass parameters as JSON or key:value lines. Do NOT add quotes/braces around values.
 8. Do NOT wrap tool calls in markdown/code fences or add any text before or after the tool block.
 
+CORRECT format — use this EXACTLY:
+<function=tool_name>
+<parameter=param_name>value</parameter>
+</function>
+
+WRONG formats — NEVER use these:
+- <invoke name="tool_name"><parameter name="param_name">value</parameter></invoke>
+- <function_calls><invoke name="tool_name">...</invoke></function_calls>
+- <tool_call><tool_name>...</tool_name></tool_call>
+- {"tool_name": {"param_name": "value"}}
+- ```<function=tool_name>...</function>```
+
+Do NOT emit any extra XML tags in your output. In particular:
+- NO <thinking>...</thinking> or <thought>...</thought> blocks
+- NO <scratchpad>...</scratchpad> or <reasoning>...</reasoning> blocks
+- NO <answer>...</answer> or <response>...</response> wrappers
+If you need to reason, use the think tool. Your raw output must contain ONLY the tool call — no surrounding XML tags.
+
+Notice: use <function=X> NOT <invoke name="X">, use <parameter=X> NOT <parameter name="X">, use </function> NOT </invoke>.
+
 Example (agent creation tool):
 <function=create_agent>
 <parameter=task>Perform targeted XSS testing on the search endpoint</parameter>
diff --git a/strix/interface/streaming_parser.py b/strix/interface/streaming_parser.py
index 95e9523..2ea69fa 100644
--- a/strix/interface/streaming_parser.py
+++ b/strix/interface/streaming_parser.py
@@ -3,8 +3,11 @@ import re
 from dataclasses import dataclass
 from typing import Literal
 
+from strix.llm.utils import normalize_tool_format
+
 
 _FUNCTION_TAG_PREFIX = "<function="
+_INVOKE_TAG_PREFIX = "<invoke "
 
 _FUNC_PATTERN = re.compile(r"<function=([^>]+)>")
 _FUNC_END_PATTERN = re.compile(r"</function>")
@@ -21,9 +24,8 @@ def _get_safe_content(content: str) -> tuple[str, str]:
         return content, ""
 
     suffix = content[last_lt:]
-    target = _FUNCTION_TAG_PREFIX  # "<function="
 
-    if target.startswith(suffix):
+    if _FUNCTION_TAG_PREFIX.startswith(suffix) or _INVOKE_TAG_PREFIX.startswith(suffix):
         return content[:last_lt], suffix
 
     return content, ""
@@ -42,6 +44,8 @@ def parse_streaming_content(content: str) -> list[StreamSegment]:
     if not content:
         return []
 
+    content = normalize_tool_format(content)
+
     segments: list[StreamSegment] = []
 
     func_matches = list(_FUNC_PATTERN.finditer(content))
diff --git a/strix/llm/llm.py b/strix/llm/llm.py
index 50501aa..0cace0e 100644
--- a/strix/llm/llm.py
+++ b/strix/llm/llm.py
@@ -14,6 +14,7 @@ from strix.llm.memory_compressor import MemoryCompressor
 from strix.llm.utils import (
     _truncate_to_first_function,
     fix_incomplete_tool_call,
+    normalize_tool_format,
     parse_tool_invocations,
 )
 from strix.skills import load_skills
@@ -143,10 +144,12 @@ class LLM:
             delta = self._get_chunk_content(chunk)
             if delta:
                 accumulated += delta
-                if "</function>" in accumulated:
-                    accumulated = accumulated[
-                        : accumulated.find("</function>") + len("</function>")
-                    ]
+                if "</function>" in accumulated or "</invoke>" in accumulated:
+                    for end_tag in ("</function>", "</invoke>"):
+                        pos = accumulated.find(end_tag)
+                        if pos != -1:
+                            accumulated = accumulated[: pos + len(end_tag)]
+                            break
                     yield LLMResponse(content=accumulated)
                     done_streaming = 1
                     continue
@@ -155,6 +158,7 @@ class LLM:
         if chunks:
             self._update_usage_stats(stream_chunk_builder(chunks))
 
+        accumulated = normalize_tool_format(accumulated)
         accumulated = fix_incomplete_tool_call(_truncate_to_first_function(accumulated))
         yield LLMResponse(
             content=accumulated,
diff --git a/strix/llm/utils.py b/strix/llm/utils.py
index bef04ce..56caa34 100644
--- a/strix/llm/utils.py
+++ b/strix/llm/utils.py
@@ -3,6 +3,29 @@ import re
 from typing import Any
 
 
+_INVOKE_OPEN = re.compile(r'<invoke\s+name="([^"]+)"\s*>')
+_PARAM_NAME_ATTR = re.compile(r'<parameter\s+name="([^"]+)"\s*>')
+_FUNCTION_CALLS_TAG = re.compile(r"</?function_calls>")
+
+
+def normalize_tool_format(content: str) -> str:
+    """Convert alternative tool-call XML format to the expected one.
+
+    Handles:
+      <function_calls>...</function_calls>  → stripped
+      <invoke name="X">                     → <function=X>
+      <parameter name="X">                  → <parameter=X>
+      </invoke>                             → </function>
+    """
+    if "<invoke" not in content and "<function_calls" not in content:
+        return content
+
+    content = _FUNCTION_CALLS_TAG.sub("", content)
+    content = _INVOKE_OPEN.sub(r"<function=\1>", content)
+    content = _PARAM_NAME_ATTR.sub(r"<parameter=\1>", content)
+    return content.replace("</invoke>", "</function>")
+
+
 STRIX_MODEL_MAP: dict[str, str] = {
     "claude-sonnet-4.6": "anthropic/claude-sonnet-4-6",
     "claude-opus-4.6": "anthropic/claude-opus-4-6",
@@ -41,7 +64,9 @@ def _truncate_to_first_function(content: str) -> str:
     if not content:
         return content
 
-    function_starts = [match.start() for match in re.finditer(r"<function=", content)]
+    function_starts = [
+        match.start() for match in re.finditer(r"<function=|<invoke\s+name=", content)
+    ]
 
     if len(function_starts) >= 2:
         second_function_start = function_starts[1]
@@ -52,6 +77,7 @@ def _truncate_to_first_function(content: str) -> str:
 
 
 def parse_tool_invocations(content: str) -> list[dict[str, Any]] | None:
+    content = normalize_tool_format(content)
     content = fix_incomplete_tool_call(content)
 
     tool_invocations: list[dict[str, Any]] = []
@@ -81,12 +107,14 @@ def parse_tool_invocations(content: str) -> list[dict[str, Any]] | None:
 
 
 def fix_incomplete_tool_call(content: str) -> str:
-    """Fix incomplete tool calls by adding missing </function> tag."""
-    if (
-        "<function=" in content
-        and content.count("<function=") == 1
-        and "</function>" not in content
-    ):
+    """Fix incomplete tool calls by adding missing closing tag.
+
+    Handles both ``<function=…>`` and ``<invoke name="…">`` formats.
+    """
+    has_open = "<function=" in content or "<invoke " in content
+    count_open = content.count("<function=") + content.count("<invoke ")
+    has_close = "</function>" in content or "</invoke>" in content
+    if has_open and count_open == 1 and not has_close:
         content = content.rstrip()
         content = content + "function>" if content.endswith("</") else content + "\n</function>"
     return content
@@ -107,6 +135,7 @@ def clean_content(content: str) -> str:
     if not content:
         return ""
 
+    content = normalize_tool_format(content)
     content = fix_incomplete_tool_call(content)
 
     tool_pattern = r"<function=[^>]+>.*?</function>"