X_MCP_CONFIRMATION_EVIDENCE_INVALID
Means
an MCP confirmation approval carries no valid signed evidence
Typical cause
mcpConfirmations({ evidence }) is declared and an approval's signature is missing, does not verify against the approver's registered keys, signs another confirmation's payload, or the stored approvals no longer meet the quorum
Fix
confirmations({ id, decision: 'view' }) — sign the signingPayload it returns with a key registered to you, then approve with that signature and exactly the arguments it returns