Function config_unusable 

fn config_unusable(e: ConfigError) -> ErrorEnvelope

A configuration that could not be resolved, as the envelope every tool call will return.

Deterministic and non-retryable: nothing the server does will fix it, so the message is the resolver’s own, which names the missing field and the flag/variable that supplies it.

The code is picked per variant rather than fixed. suggested_action is serialized into the tool result the user reads (ghidra-ipc/src/error.rs), and GhidraNotFound carries “point GHIDRA_INSTALL_DIR at your Ghidra install root” — a wrong instruction for someone whose install is fine and whose project settings are not. The action is overridden too, because every one of these is a settings problem and none of the code-level hints says so.