docs: improve tool documentation and examples

- Update SerperDevTool documentation with accurate parameters and JSON response format
- Enhance XMLSearchTool and MDXSearchTool docs with RAG capabilities and required parameters
- Fix code block formatting across multiple tool documentation files
- Add clarification about environment variables and configuration
- Validate all examples against actual implementations
- Successfully tested with mkdocs build

Co-Authored-By: Joe Moura <joao@crewai.com>

docs/tools/composiotool.mdx

@@ -27,7 +27,7 @@ The following example demonstrates how to initialize the tool and execute a gith
 
 1. Initialize Composio tools
 
-```python Code
+```python
 from composio import App
 from crewai_tools import ComposioTool
 from crewai import Agent, Task
@@ -38,19 +38,19 @@ tools = [ComposioTool.from_action(action=Action.GITHUB_ACTIVITY_STAR_REPO_FOR_AU
 
 If you don't know what action you want to use, use `from_app` and `tags` filter to get relevant actions
 
-```python Code
+```python
 tools = ComposioTool.from_app(App.GITHUB, tags=["important"])
 ```
 
 or use `use_case` to search relevant actions
 
-```python Code
+```python
 tools = ComposioTool.from_app(App.GITHUB, use_case="Star a github repository")
 ```
 
 2. Define agent
 
-```python Code
+```python
 crewai_agent = Agent(
     role="Github Agent",
     goal="You take action on Github using Github APIs",
@@ -65,7 +65,7 @@ crewai_agent = Agent(
 
 3. Execute task
 
-```python Code
+```python
 task = Task(
     description="Star a repo ComposioHQ/composio on GitHub",
     agent=crewai_agent,
@@ -75,4 +75,4 @@ task = Task(
 task.execute()
 ```
 
-* More detailed list of tools can be found [here](https://app.composio.dev)
+* More detailed list of tools can be found [here](https://app.composio.dev)