fix(display): strip standalone tool-call XML tags from visible text

Port from openclaw/openclaw#67318. Some open models (notably Gemma
variants served via OpenRouter) emit tool calls as XML blocks inside
assistant content instead of via the structured tool_calls field:

  <function name="read_file"><parameter name="path">/tmp/x</parameter></function>
  <tool_call>{"name":"x"}</tool_call>
  <function_calls>[{...}]</function_calls>

Left unstripped, this raw XML leaked to gateway users (Discord, Telegram,
Matrix, Feishu, Signal, WhatsApp, etc.) and the CLI, since hermes-agent's
existing reasoning-tag stripper handled only <think>/<thinking>/<thought>
variants.

Extend _strip_think_blocks (run_agent.py) and _strip_reasoning_tags
(cli.py) to cover:
  * <tool_call>, <tool_calls>, <tool_result>
  * <function_call>, <function_calls>
  * <function name="..."> ... </function> (Gemma-style)

The <function> variant is boundary-gated (only strips when the tag sits
at start-of-line or after sentence punctuation AND carries a name="..."
attribute) so prose mentions like 'Use <function> declarations in JS'
are preserved. Dangling <function name="..."> with no close is
intentionally left visible — matches OpenClaw's asymmetry so a truncated
streaming tail still reaches the user.

Tests: 9 new cases in TestStripThinkBlocks (run_agent) + 9 in new file
tests/run_agent/test_strip_reasoning_tags_cli.py. Covers Qwen-style
<tool_call>, Gemma-style <function name="...">, multi-line payloads,
prose preservation, stray close tags, dangling open tags, and mixed
reasoning+tool_call content.

Note: this port covers the post-streaming final-text path, which is what
gateway adapters and CLI display consume. Extending the per-delta stream
filter in gateway/stream_consumer.py to hide these tags live as they
stream is a separate follow-up; for now users may see raw XML briefly
during a stream before the final cleaned text replaces it.

Refs: openclaw/openclaw#67318

tests/run_agent/test_run_agent.py

@@ -372,6 +372,91 @@ class TestStripThinkBlocks:
         assert "mixed" not in result
         assert "final" in result
 
+    # ─── Tool-call XML block stripping (openclaw/openclaw#67318) ─────────
+    # Some open models (notably Gemma variants via OpenRouter) emit
+    # standalone tool-call XML inside assistant content instead of via the
+    # structured `tool_calls` field. Left unstripped, raw XML leaks to
+    # gateway users (Discord/Telegram/Matrix) and the CLI.
+
+    def test_tool_call_block_stripped(self, agent):
+        text = '<tool_call>{"name": "read_file", "arguments": {"path": "/tmp/x"}}</tool_call> done'
+        result = agent._strip_think_blocks(text)
+        assert "<tool_call>" not in result
+        assert "read_file" not in result
+        assert "done" in result
+
+    def test_function_calls_block_stripped(self, agent):
+        text = '<function_calls>[{"name":"x"}]</function_calls>after'
+        result = agent._strip_think_blocks(text)
+        assert "<function_calls>" not in result
+        assert "after" in result
+
+    def test_gemma_function_name_block_stripped(self, agent):
+        """Gemma-style: <function name="read"><parameter>...</parameter></function>."""
+        text = (
+            'Let me check the file.\n'
+            '<function name="read_file"><parameter name="path">/tmp/x.md</parameter></function>\n'
+            'Here is the result.'
+        )
+        result = agent._strip_think_blocks(text)
+        assert '<function name="read_file">' not in result
+        assert "/tmp/x.md" not in result
+        assert "Let me check the file." in result
+        assert "Here is the result." in result
+
+    def test_gemma_function_multiline_payload_stripped(self, agent):
+        text = (
+            'Reading now.\n'
+            '<function name="read_file">\n'
+            '  <parameter name="path">/etc/passwd</parameter>\n'
+            '</function>\n'
+            'Done.'
+        )
+        result = agent._strip_think_blocks(text)
+        assert "/etc/passwd" not in result
+        assert "Reading now." in result
+        assert "Done." in result
+
+    def test_function_mention_in_prose_preserved(self, agent):
+        """'Use <function> in JavaScript.' — no name attr, not at block boundary
+        in a way that suggests tool call. Must survive."""
+        text = "In JS you can use <function> declarations for hoisting."
+        result = agent._strip_think_blocks(text)
+        # Prose mention has no name="..." attribute -> not stripped
+        assert "declarations for hoisting" in result
+
+    def test_function_with_attr_in_middle_of_sentence_preserved(self, agent):
+        """Docs example: 'Use <function name="x">...</function> in docs.'
+        The sentence-middle position without a preceding punctuation block
+        boundary means it is NOT stripped. Prose context remains."""
+        text = 'You can write <function name="x">y</function> inline.'
+        result = agent._strip_think_blocks(text)
+        # Without a leading block boundary (no punctuation before), leaves intact
+        assert "You can write" in result
+        assert "inline" in result
+
+    def test_stray_function_close_tag_removed(self, agent):
+        text = "answer</function> trailing"
+        result = agent._strip_think_blocks(text)
+        assert "</function>" not in result
+        assert "answer" in result
+        assert "trailing" in result
+
+    def test_dangling_function_open_tag_preserved(self, agent):
+        """A streamed-but-truncated <function name="..."> block with no close
+        is intentionally NOT stripped (OpenClaw's asymmetry). The tail of a
+        streaming reply may still be valuable to the user."""
+        text = 'Checking: <function name="read">'
+        result = agent._strip_think_blocks(text)
+        assert "Checking:" in result
+
+    def test_mixed_reasoning_and_tool_call_both_stripped(self, agent):
+        text = '<think>let me plan</think><tool_call>{"name":"x"}</tool_call>final answer'
+        result = agent._strip_think_blocks(text)
+        assert "let me plan" not in result
+        assert "<tool_call>" not in result
+        assert "final answer" in result
+
 
 class TestExtractReasoning:
     def test_reasoning_field(self, agent):

tests/run_agent/test_strip_reasoning_tags_cli.py

@@ -0,0 +1,69 @@
+"""Tests for cli.py::_strip_reasoning_tags — specifically the tool-call
+XML stripping added in openclaw/openclaw#67318 port.
+
+The CLI has its own copy of the stripper because it needs to run on the
+final displayed assistant text (after streaming) without depending on the
+AIAgent instance. It must stay in sync with run_agent.py::_strip_think_blocks
+for tool-call tag coverage."""
+
+import pytest
+
+from cli import _strip_reasoning_tags
+
+
+class TestToolCallStripping:
+    def test_tool_call_block_stripped(self):
+        text = '<tool_call>{"name": "x"}</tool_call>result'
+        result = _strip_reasoning_tags(text)
+        assert "<tool_call>" not in result
+        assert "result" in result
+
+    def test_function_calls_block_stripped(self):
+        text = '<function_calls>[{}]</function_calls>\nanswer'
+        result = _strip_reasoning_tags(text)
+        assert "<function_calls>" not in result
+        assert "answer" in result
+
+    def test_gemma_function_name_block_stripped(self):
+        text = (
+            'Reading.\n'
+            '<function name="r"><parameter name="p">/tmp/x</parameter></function>\n'
+            'Done.'
+        )
+        result = _strip_reasoning_tags(text)
+        assert '<function name="r">' not in result
+        assert "/tmp/x" not in result
+        assert "Reading." in result
+        assert "Done." in result
+
+    def test_prose_mention_of_function_preserved(self):
+        text = "Use <function> declarations in JavaScript."
+        result = _strip_reasoning_tags(text)
+        assert "JavaScript" in result
+
+    def test_reasoning_still_stripped(self):
+        """Regression: make sure existing think-tag stripping still works."""
+        text = "<think>reasoning</think> answer"
+        result = _strip_reasoning_tags(text)
+        assert "reasoning" not in result
+        assert "answer" in result
+
+    def test_mixed_reasoning_and_tool_call(self):
+        text = '<think>plan</think><tool_call>{"x":1}</tool_call>final'
+        result = _strip_reasoning_tags(text)
+        assert "plan" not in result
+        assert "<tool_call>" not in result
+        assert "final" in result
+
+    def test_stray_function_close(self):
+        text = "visible</function> tail"
+        result = _strip_reasoning_tags(text)
+        assert "</function>" not in result
+        assert "visible" in result
+        assert "tail" in result
+
+    def test_empty_string(self):
+        assert _strip_reasoning_tags("") == ""
+
+    def test_plain_text_unchanged(self):
+        assert _strip_reasoning_tags("just text") == "just text"