perf: update FileReadTool description to mention image, PDF and docx support, and enhance modality checking in tool result case (#7506)

* feat: update FileReadTool description to mention image and PDF support

Add explicit mention of image (OCR) and PDF (text extraction) support
to the FileReadTool description for better discoverability.

* feat: update FileReadTool description to include support for docx and epub files; change base64 decoding to utf-8

* feat: enhance ToolLoopAgentRunner to support image and audio modalities; add context sanitization logic

tests/unit/test_astr_main_agent.py

@@ -713,144 +713,6 @@ class TestDecorateLlmRequest:
         assert req.prompt == "Hello"
 
 
-class TestModalitiesFix:
-    """Tests for _modalities_fix function."""
-
-    def test_modalities_fix_image_not_supported(self, mock_provider):
-        """Test modality fix when image is not supported."""
-        module = ama
-        mock_provider.provider_config = {"modalities": ["text"]}
-        req = ProviderRequest(prompt="Hello", image_urls=["/path/to/image.jpg"])
-
-        module._modalities_fix(mock_provider, req)
-
-        assert "[Image]" in req.prompt
-        assert req.image_urls == []
-
-    def test_modalities_fix_tool_not_supported(self, mock_provider):
-        """Test modality fix when tool is not supported."""
-        module = ama
-        mock_provider.provider_config = {"modalities": ["text", "image"]}
-        req = ProviderRequest(prompt="Hello")
-        req.func_tool = ToolSet()
-        req.func_tool.add_tool(
-            FunctionTool(
-                name="dummy_tool",
-                description="dummy",
-                parameters={"type": "object", "properties": {}},
-            )
-        )
-
-        module._modalities_fix(mock_provider, req)
-
-        assert req.func_tool is None
-
-    def test_modalities_fix_all_supported(self, mock_provider):
-        """Test modality fix when all features are supported."""
-        module = ama
-        mock_provider.provider_config = {"modalities": ["image", "tool_use"]}
-        tool_set = ToolSet()
-        tool_set.add_tool(
-            FunctionTool(
-                name="dummy_tool",
-                description="dummy",
-                parameters={"type": "object", "properties": {}},
-            )
-        )
-        req = ProviderRequest(
-            prompt="Hello",
-            image_urls=["/path/to/image.jpg"],
-            func_tool=tool_set,
-        )
-
-        module._modalities_fix(mock_provider, req)
-
-        assert req.prompt == "Hello"
-        assert len(req.image_urls) == 1
-        assert req.func_tool is not None
-
-
-class TestSanitizeContextByModalities:
-    """Tests for _sanitize_context_by_modalities function."""
-
-    def test_sanitize_no_op(self, mock_provider):
-        """Test sanitize when disabled or modalities support everything."""
-        module = ama
-        config = module.MainAgentBuildConfig(
-            tool_call_timeout=60, sanitize_context_by_modalities=False
-        )
-        mock_provider.provider_config = {"modalities": ["image", "tool_use"]}
-        req = ProviderRequest(contexts=[{"role": "user", "content": "Hello"}])
-
-        module._sanitize_context_by_modalities(config, mock_provider, req)
-
-        assert len(req.contexts) == 1
-
-    def test_sanitize_removes_tool_messages(self, mock_provider):
-        """Test sanitize removes tool messages when tool_use not supported."""
-        module = ama
-        config = module.MainAgentBuildConfig(
-            tool_call_timeout=60, sanitize_context_by_modalities=True
-        )
-        mock_provider.provider_config = {"modalities": ["image"]}
-        req = ProviderRequest(
-            contexts=[
-                {"role": "user", "content": "Hello"},
-                {"role": "tool", "content": "Tool result"},
-            ]
-        )
-
-        module._sanitize_context_by_modalities(config, mock_provider, req)
-
-        assert len(req.contexts) == 1
-        assert req.contexts[0]["role"] == "user"
-
-    def test_sanitize_removes_tool_calls(self, mock_provider):
-        """Test sanitize removes tool_calls from assistant messages."""
-        module = ama
-        config = module.MainAgentBuildConfig(
-            tool_call_timeout=60, sanitize_context_by_modalities=True
-        )
-        mock_provider.provider_config = {"modalities": ["image"]}
-        req = ProviderRequest(
-            contexts=[
-                {
-                    "role": "assistant",
-                    "content": "Response",
-                    "tool_calls": [{"name": "tool"}],
-                }
-            ]
-        )
-
-        module._sanitize_context_by_modalities(config, mock_provider, req)
-
-        assert "tool_calls" not in req.contexts[0]
-
-    def test_sanitize_removes_image_blocks(self, mock_provider):
-        """Test sanitize removes image blocks when image not supported."""
-        module = ama
-        config = module.MainAgentBuildConfig(
-            tool_call_timeout=60, sanitize_context_by_modalities=True
-        )
-        mock_provider.provider_config = {"modalities": ["tool_use"]}
-        req = ProviderRequest(
-            contexts=[
-                {
-                    "role": "user",
-                    "content": [
-                        {"type": "text", "text": "Hello"},
-                        {"type": "image_url", "url": "image.jpg"},
-                    ],
-                }
-            ]
-        )
-
-        module._sanitize_context_by_modalities(config, mock_provider, req)
-
-        assert len(req.contexts[0]["content"]) == 1
-        assert req.contexts[0]["content"][0]["type"] == "text"
-
-
 class TestPluginToolFix:
     """Tests for _plugin_tool_fix function."""