fix(runtime): preserve MCP tool inputSchema from SDK fields

[AchuthReddy-16]

Summary

McpIntegration.list_tools() always returned an empty inputSchema for MCP tools even when the server provided a schema.

The MCP SDK exposes the field as input_schema in Python, while inputSchema is the JSON alias. The existing code only checked inputSchema, so the lookup missed the actual SDK field and fell back to {}.

This change reads input_schema first while preserving inputSchema as a fallback for compatible stubs. The fake MCP tool used in tests was also updated to match the real SDK shape, and a regression test verifies that list_tools() preserves the schema.

Fixes #1073

Test plan

Ran:

PYTHONPATH=src python3 -m unittest discover -s test -p 'test_mcp_base.py' -v

The new test_list_tools_keeps_input_schema case passed along with the existing MCP tool-call coverage.

Note

Fix McpIntegration tool discovery to preserve input_schema from MCP SDK

The MCP SDK's Tool type uses the snake_case attribute input_schema, but the cache population code in mcp_base.py only read inputSchema, causing schemas to be silently dropped to {}. The fix reads input_schema first, falling back to inputSchema, then an empty dict, and stores the result under inputSchema in the internal cache.

^{Macroscope summarized 5d88631.}

[sethkarten]

Thank you for the report and proposed work. This root cause is now covered by maintainer-owned stacked PR #1164, authored independently from upstream/main.

We did not inspect or reuse this PR's diff, branch, commits, implementation code, or tests; its public description/comments were used only as a bug report. To keep one review surface, this PR is superseded by #1164 and is being closed.

The complete review stack is #1158–#1165. It is being left unmerged for human review after CI and review-bot findings are cleared.