fix: support additional Tavily search parameters via configuration to fix #548 (#643)

* fix: support additional Tavily search parameters via configuration to fix #548

- Add include_answer, search_depth, include_raw_content, include_images, include_image_descriptions to SEARCH_ENGINE config
- Update get_web_search_tool() to load these parameters from configuration with sensible defaults
- Parameters are now properly passed to TavilySearchWithImages during initialization
- This fixes 'got an unexpected keyword argument' errors when using web_search tool
- Update tests to verify new parameters are correctly set

* test: add comprehensive unit tests for web search configuration loading

- Add test for custom configuration values (include_answer, search_depth, etc.)
- Add test for empty configuration (all defaults)
- Add test for image_descriptions logic when include_images is false
- Add test for partial configuration
- Add test for missing config file
- Add test for multiple domains in include/exclude lists

All 7 new tests pass and provide comprehensive coverage of configuration loading
and parameter handling for Tavily search tool initialization.

* test: verify all Tavily configuration parameters are optional

Add 8 comprehensive tests to verify that all Tavily engine configuration
parameters are truly optional:

- test_tavily_with_no_search_engine_section: SEARCH_ENGINE section missing
- test_tavily_with_completely_empty_config: Entire config missing
- test_tavily_with_only_include_answer_param: Single param, rest default
- test_tavily_with_only_search_depth_param: Single param, rest default
- test_tavily_with_only_include_domains_param: Domain param, rest default
- test_tavily_with_explicit_false_boolean_values: False values work correctly
- test_tavily_with_empty_domain_lists: Empty lists handled correctly
- test_tavily_all_parameters_optional_mix: Multiple missing params work

These tests verify:
- Tool creation never fails regardless of missing configuration
- All parameters have sensible defaults
- Boolean parameters can be explicitly set to False
- Any combination of optional parameters works
- Domain lists can be empty or omitted

All 15 Tavily configuration tests pass successfully.

src/tools/search.py

@@ -47,22 +47,29 @@ def get_web_search_tool(max_search_results: int):
     search_config = get_search_config()
 
     if SELECTED_SEARCH_ENGINE == SearchEngine.TAVILY.value:
-        # Only get and apply include/exclude domains for Tavily
+        # Get all Tavily search parameters from configuration with defaults
         include_domains: Optional[List[str]] = search_config.get("include_domains", [])
         exclude_domains: Optional[List[str]] = search_config.get("exclude_domains", [])
-        include_raw_content = search_config.get("include_raw_content", True)
-        include_images: Optional[bool] = search_config.get("include_images", True)
-        include_image_descriptions: Optional[bool] = (
+        include_answer: bool = search_config.get("include_answer", False)
+        search_depth: str = search_config.get("search_depth", "advanced")
+        include_raw_content: bool = search_config.get("include_raw_content", True)
+        include_images: bool = search_config.get("include_images", True)
+        include_image_descriptions: bool = (
             include_images and search_config.get("include_image_descriptions", True)
         )
 
         logger.info(
-            f"Tavily search configuration loaded: include_domains={include_domains}, exclude_domains={exclude_domains}"
+            f"Tavily search configuration loaded: include_domains={include_domains}, "
+            f"exclude_domains={exclude_domains}, include_answer={include_answer}, "
+            f"search_depth={search_depth}, include_raw_content={include_raw_content}, "
+            f"include_images={include_images}, include_image_descriptions={include_image_descriptions}"
         )
 
         return LoggedTavilySearch(
             name="web_search",
             max_results=max_search_results,
+            include_answer=include_answer,
+            search_depth=search_depth,
             include_raw_content=include_raw_content,
             include_images=include_images,
             include_image_descriptions=include_image_descriptions,