Server crashes on startup with mcp SDK 2.0.0 (2026-07-28): AttributeError: 'Tool' object has no attribute 'inputSchema'

[PapiScholz]

Describe the bug:

The mcp Python SDK published 2.0.0 on PyPI today (2026-07-28). Fresh installs of analytics-mcp (via pipx run or uvx) now resolve to the new SDK and crash immediately on startup, because this package has no upper bound on its mcp dependency.

Traceback:

File "...\site-packages\analytics_mcp\coordinator.py", line 125, in
if tool.inputSchema == {}:
File "...\site-packages\pydantic\main.py", line 1042, in getattr
raise AttributeError(f'{type(self).name!r} object has no attribute {item!r}')
AttributeError: 'Tool' object has no attribute 'inputSchema'. Did you mean: 'input_schema'?

Root cause: mcp 2.0.0 renamed Tool.inputSchema to Tool.input_schema (snake_case). coordinator.py line 125 still uses the old attribute name.

Steps to Reproduce:

1. Run uvx analytics-mcp (or pipx run analytics-mcp) with valid GOOGLE_APPLICATION_CREDENTIALS on any machine without a previously cached mcp<2 environment.
2. The process exits with the traceback above. uvx --refresh does not help — the dependency resolution itself is broken, not the cache.

Expected behavior:

The server starts and serves its tools over stdio, as it did with mcp 1.x (working as recently as yesterday, 2026-07-27).

Anything else we should know about your project / environment:

• Windows 11, uv 0.11.x. The related project mcp-gsc is broken by the same SDK release (ModuleNotFoundError: No module named 'mcp.server.fastmcp') — reported at Server fails to start after mcp SDK 2.0.0 (2026-07-28): ModuleNotFoundError: No module named 'mcp.server.fastmcp' AminForou/mcp-gsc#41 — so this affects the whole mcp 1.x server ecosystem, not just this package.
• Working workaround for users: uvx --with "mcp<2" analytics-mcp (verified).
• Suggested fix: pin mcp>=1,<2 in the package dependencies, or update coordinator.py to input_schema.
• Found while building search-visibility-kit, a Claude plugin that bundles this server with the pin already applied.

[PapiScholz]

Thanks for the fast turnaround!

Note for anyone landing here: the fix (#200) is merged, but as of this writing PyPI still serves 0.6.0 (pre-fix), so fresh installs will keep crashing until a new release ships. In the meantime, this works:

uvx --with "mcp<2" analytics-mcp