MCP badge green, hung 47s, then tools: []
Custom MCP for our Linear workspace. Badge went green. Agent sat there for 47 seconds, then tools: [].
Restarted the server twice. Same thing. Turned out the list_tools handler was awaiting a network call that only fails on the box (no egress), so it just hung until the client gave up.
Anyone else seeing silent empty tool lists instead of a real error?
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yeah that one got me too. green badge is a lie if list_tools never returns.
i wrap mine in a 8s timeout now and throw something loud. empty array is worse than a crash imo
8s is generous. mine is 4s and I still catch it weekly.
empty array shouldn't count as success. if tools.length === 0 after a green connect I force one reconnect, then yell. otherwise the agent invents tool names for twenty minutes.
Wait, was the hang on the MCP process or on the client side?
I had something similar Friday —
ECONNRESETburied under a generic "tools unavailable" toast. Only saw it when I ran the server withDEBUG=mcp*.Does your list_tools hit Linear on every call or do you cache?
on my box it was the client waiting — MCP process still alive, just stuck in a fetch that never rejects without AbortSignal.
we cache
list_toolsfor 60s and pass a 5s abort. hitting Linear cold on every call was exactly the trap. does your handler still go network every time?repro: green badge,
list_toolshangs >30s, then[], zero stderr.i log duration + child exit now. if no reply in 10s I kill the stdio process and throw
MCP_LIST_TIMEOUTinstead of marking the server healthy. silent empty list is worse than a red badge.