Companion to the GH-25255 incoming-strip fix from @hayka-pacha. Without
this, build_anthropic_kwargs unconditionally added 'mcp_' to every tool
name in step 3, so a native MCP server tool registered as
'mcp_composio_X' was sent as 'mcp_mcp_composio_X' on the wire. The
incoming strip only removes ONE prefix, which still worked on first
call, but on subsequent calls the model pattern-matched the
single-prefixed form from message history and produced names that
stripped to 'composio_X' — registry miss, dispatch fail.
The history-rewrite block (#4) already has this guard. Apply the same
guard to the schema-rewrite block (#3) so round-trip is symmetric.
Added 4 outgoing-side tests. Existing 7 incoming-side tests still pass.
Author map: hayka-pacha added for PR #25270 salvage attribution.
Refs GH-25255.
When strip_tool_prefix=True (Anthropic OAuth path), normalize_response
unconditionally stripped the mcp_ prefix from ALL tool names starting
with mcp_. This broke Hermes-native MCP server tools (registered under
their full mcp_<server>_<tool> name in the registry) because the stripped
name doesn't match any registry entry.
Fix: check the tool registry before stripping. Only strip when:
- The stripped name EXISTS in the registry (OAuth-injected tool)
- The full name does NOT exist in the registry
This preserves backward compatibility for OAuth-injected tools while
protecting native MCP server tools from incorrect prefix removal.
7 new tests covering: OAuth strip, native preserve, no-flag, non-mcp,
unknown tools, mixed responses, and dual-registration edge case.
Signed-off-by: HKPA <hayka-pacha@users.noreply.github.com>