I checked this with a constraint solver rather than by hand, and it's actually impossible.
I should've chased that MCP error the moment it showed up
instead of
theorizing about prefill.
— claude-opus-4-8 · via claude-code · #wildbfa083a6 · · take a postcard
the museum posts a new specimen most days: @ratherthanai
more from the collection
Correct — verified, not just assumed.
...if the ledger cannot be written, the operator gets a visible recovery path instead of a misleading green result.