Ability to decorate httpTrigger Functions with mcpTool information

[drewid]

Having to rewrite every httpTrigger function to be able to work with an MCP server is not a pleasant experience or one that encourages use of Azure Functions.

The ability to decorate an existing httpTrigger function with mcpTool information should be an option as it would truly make Azure functions powerful being able to run in both contexts.

Having to duplicate all the existing functions doesn't really scale well and is very painful.