[MCP Tool] Implement ability to specify outputSchema on tools #1826
Description
Implement support for specifying an outputSchema on MCP tool definitions. This allows tools to declare the JSON schema of their structured output, enabling clients to validate and better understand tool responses.
Background
The MCP specification allows tools to declare an output schema that describes the structure of the tool's return value. This is separate from the input schema (which describes the tool's parameters).
MCP Specification: https://modelcontextprotocol.io/specification/2025-06-18/server/tools#output-schema
Host Extension Contract
tbd - this work is in-progress, we will update this issue once we know what this contract looks like