fix: parse MCP result payloads and drop place idempotency_key

Typed result structs replace empty envelopes. Equity place sends
ref_id only so live additionalProperties:false schemas accept the call.

options/read.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"time"
 
+	decimal "github.com/alpacahq/alpacadecimal"
 	"s1d3sw1ped/robinhood-agentic-mcp/client"
 	"s1d3sw1ped/robinhood-agentic-mcp/internal/wire"
 )
@@ -24,8 +25,17 @@ type ChainsRequest struct {
 	UnderlyingSymbol string
 }
 
+// OptionChain is one chain from get_option_chains.
+type OptionChain struct {
+	ID               string
+	UnderlyingSymbol string
+	ExpirationDates  []string
+}
+
 // ChainsResult is the parsed get_option_chains payload.
-type ChainsResult struct{}
+type ChainsResult struct {
+	Chains []OptionChain
+}
 
 // InstrumentsRequest is the argument set for get_option_instruments.
 type InstrumentsRequest struct {
@@ -40,16 +50,42 @@ type InstrumentsRequest struct {
 	Cursor          string
 }
 
+// OptionInstrument is one contract from get_option_instruments.
+type OptionInstrument struct {
+	ID             string
+	ChainID        string
+	ChainSymbol    string
+	ExpirationDate string
+	StrikePrice    decimal.Decimal
+	Type           string
+	State          string
+}
+
 // InstrumentsResult is the parsed get_option_instruments payload.
-type InstrumentsResult struct{}
+type InstrumentsResult struct {
+	Instruments []OptionInstrument
+	NextCursor  string
+}
 
 // QuotesRequest is the argument set for get_option_quotes.
 type QuotesRequest struct {
 	InstrumentIDs []string
 }
 
+// OptionQuote is one contract quote from get_option_quotes.
+type OptionQuote struct {
+	InstrumentID string
+	Bid          decimal.Decimal
+	Ask          decimal.Decimal
+	Last         decimal.Decimal
+	PrevClose    decimal.Decimal
+	Mark         decimal.Decimal
+}
+
 // QuotesResult is the parsed get_option_quotes payload.
-type QuotesResult struct{}
+type QuotesResult struct {
+	Quotes []OptionQuote
+}
 
 // PositionsRequest is the argument set for get_option_positions.
 type PositionsRequest struct {
@@ -65,8 +101,22 @@ type PositionsRequest struct {
 	Cursor            string
 }
 
+// OptionPosition is one holding from get_option_positions.
+type OptionPosition struct {
+	OptionID       string
+	ChainID        string
+	Type           string
+	OptionType     string
+	Quantity       decimal.Decimal
+	AveragePrice   decimal.Decimal
+	ExpirationDate string
+}
+
 // PositionsResult is the parsed get_option_positions payload.
-type PositionsResult struct{}
+type PositionsResult struct {
+	Positions  []OptionPosition
+	NextCursor string
+}
 
 // OrdersRequest is the argument set for get_option_orders.
 type OrdersRequest struct {
@@ -81,7 +131,10 @@ type OrdersRequest struct {
 }
 
 // OrdersResult is the parsed get_option_orders payload.
-type OrdersResult struct{}
+type OrdersResult struct {
+	Orders     []Order
+	NextCursor string
+}
 
 // HistoricalsRequest is the argument set for get_option_historicals.
 type HistoricalsRequest struct {
@@ -92,8 +145,19 @@ type HistoricalsRequest struct {
 	Bounds        string
 }
 
+// OptionBar is one OHLC bar from get_option_historicals.
+type OptionBar struct {
+	InstrumentID           string
+	Time                   time.Time
+	Open, High, Low, Close decimal.Decimal
+	Volume                 decimal.Decimal
+	Interpolated           bool
+}
+
 // HistoricalsResult is the parsed get_option_historicals payload.
-type HistoricalsResult struct{}
+type HistoricalsResult struct {
+	Bars []OptionBar
+}
 
 // Chains calls get_option_chains.
 func (c *Client) Chains(ctx context.Context, req ChainsRequest) (ChainsResult, error) {