clarify flag usage + check fireblocks flags all set

flags.go

@@ -77,29 +77,29 @@ var (
 	}
 	EcdsaPrivateKeyFlag = cli.StringFlag{
 		Name:   "ecdsa-private-key",
-		Usage:  "Ethereum ecdsa private key",
+		Usage:  "Ethereum ecdsa private key. If not set, Fireblocks credentials must be set.",
 		EnvVar: envVarPrefix + "ECDSA_PRIVATE_KEY",
 	}
 	// Fireblocks flags
 	FireblocksAPIKeyFlag = cli.StringFlag{
 		Name:   "fireblocks-api-key",
-		Usage:  "Fireblocks API Key",
+		Usage:  "Fireblocks API Key. Ignored if ecdsa-private-key is set.",
 		EnvVar: envVarPrefix + "FIREBLOCKS_API_KEY",
 	}
 	FireblocksAPISecretFlag = cli.StringFlag{
 		Name:   "fireblocks-api-secret",
-		Usage:  "Fireblocks API Secret",
+		Usage:  "Fireblocks API Secret. Ignored if ecdsa-private-key is set.",
 		EnvVar: envVarPrefix + "FIREBLOCKS_API_SECRET",
 	}
 	FireblocksBaseURLFlag = cli.StringFlag{
 		Name:   "fireblocks-api-url",
-		Usage:  "Fireblocks API URL",
+		Usage:  "Fireblocks API URL. Ignored if ecdsa-private-key is set.",
 		EnvVar: envVarPrefix + "FIREBLOCKS_API_URL",
 		Value:  "https://api.fireblocks.io",
 	}
 	FireblocksVaultAccountNameFlag = cli.StringFlag{
 		Name:   "fireblocks-vault-account-name",
-		Usage:  "Fireblocks Vault Account Name",
+		Usage:  "Fireblocks Vault Account Name. Ignored if ecdsa-private-key is set.",
 		EnvVar: envVarPrefix + "FIREBLOCKS_VAULT_ACCOUNT_NAME",
 	}
 )

main.go

@@ -80,6 +80,18 @@ func avsSyncMain(cliCtx *cli.Context) error {
 		fbSecret := cliCtx.String(FireblocksAPISecretFlag.Name)
 		fbBaseURL := cliCtx.String(FireblocksBaseURLFlag.Name)
 		fbVaultAccountName := cliCtx.String(FireblocksVaultAccountNameFlag.Name)
+		if fbAPIKey == "" {
+			return errors.New("Fireblocks API key is not set")
+		}
+		if fbSecret == "" {
+			return errors.New("Fireblocks API secret is not set")
+		}
+		if fbBaseURL == "" {
+			return errors.New("Fireblocks base URL is not set")
+		}
+		if fbVaultAccountName == "" {
+			return errors.New("Fireblocks vault account name is not set")
+		}
 
 		fireblocksClient, err := fireblocks.NewClient(
 			fbAPIKey,