feat: Add tool annotations for improved LLM tool understanding

[bryankthompson]

Summary

Adds MCP tool annotations (readOnlyHint, destructiveHint, title) to all 22 tools to help LLMs better understand tool behavior and make safer decisions about tool execution.

Changes

• Added readOnlyHint: true to 16 read-only tools (get_, search_, login)
• Added destructiveHint: true to 6 tools that modify data:
  • place_order, modify_order, cancel_order
  • place_gtt_order, delete_gtt_order, modify_gtt_order
• Added title annotations for human-readable display

Files Modified:

File	Tools	Category
mcp/get_tools.go	9	Read-only
mcp/post_tools.go	6	Destructive
mcp/market_tools.go	5	Read-only
mcp/mf_tools.go	1	Read-only
mcp/setup_tools.go	1	Read-only

Why This Matters

• Annotations provide semantic metadata that helps LLMs understand tool behavior
• LLMs can make better decisions about when to use tools and in what order
• Enables safer tool execution by distinguishing read-only from destructive operations
• MCP clients like Claude Code can auto-approve read-only tools without user confirmation

Testing

• Server builds successfully (go build ./...)
• All tests pass (go test ./...)
• Annotation values match actual tool behavior:
  • Order placement/modification/cancellation → destructive
  • Data queries and market data → read-only

Before/After

Before:

func (*PlaceOrderTool) Tool() mcp.Tool {
    return mcp.NewTool("place_order",
        mcp.WithDescription("Place an order"),
        mcp.WithString("variety", ...),
    )
}

After:

func (*PlaceOrderTool) Tool() mcp.Tool {
    return mcp.NewTool("place_order",
        mcp.WithDescription("Place an order"),
        mcp.WithTitleAnnotation("Place Order"),
        mcp.WithDestructiveHintAnnotation(true),
        mcp.WithString("variety", ...),
    )
}

🤖 Generated with Claude Code