ROB-005: 1 MB and 10 MB requests are answered or rejected, never dropped

Severity	Applies to	Spec section
error	both eras, stdio, http	2026-07-28/basic/index#messages

Sends a tools/list request padded to 1 MB, then one padded to 10 MB, through a vendor-prefixed _meta key (com.mcpprobe/padding) that servers must not interpret (https://modelcontextprotocol.io/specification/2026-07-28/basic/index#meta). All messages MUST follow JSON-RPC 2.0, which requires a response to every request. The server may answer, or refuse with a JSON-RPC error or, on HTTP, a 4xx status such as 413 Payload Too Large; it fails if it drops the request, closes the connection, or answers with a 5xx and no JSON-RPC error. A crash or hang fails the run through the liveness probe. Runs once per server.

From the command line: mcpprobe checks explain ROB-005. To leave it out of a run, add "ROB-005" to [checks] disable in mcpprobe.toml; to change how much it counts, use severity_overrides.