Doc: Clarify MCP Client-Server model in What is MCP section

[yuka-with-data]

This PR adds a small clarification to the MCP overview to make the client–server relationship more explicit.

Motivation and Context

Since MCP is described as a protocol for LLM applications, I thought it would be helpful to briefly note that LLM applications act as clients connecting to MCP servers. This additional context helps complete the mental model without changing the existing structure or adding complexity. Everything else remains unchanged.

How Has This Been Tested?

Breaking Changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

I did not open a separate issue for this PR since the change is a small documentation clarification, which appears to fall under the “docs tweak” category in the contribution guidelines. Happy to adjust if a linked issue is preferred.