The per-row MCP Test button derived its presentation solely from the test
mutation's data ({ ok, tools } | { ok, error }). When the request itself
rejected (401/403/500/network) there is no payload, so the row silently spun
back to the idle "Test" instead of reporting the failure.
Feed the mutation error into mcpTestButtonView so a reject also renders a red
"Failed", with the tooltip taken from the server message
(error.response.data.message) or a generic i18n fallback. Enable the tooltip
for any non-idle state. Cover the reject branch (with and without a server
message) in the helper unit test.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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