bug: StructuredContent not parsed in utils.ParseCallToolResult

[Suvigo]

Description

When I use the NewStreamableHttpClient of mcp-go version 0.36.0 to perform the callTool operation, I return mcp.NewToolResultStructuredOnly(result) or mcp.NewToolResultStructured(result, "SUCCESS") on the server side. The result is a struct structure. The local test server result struct is as follows:

However, when I use mcp-client to execute the tool through the tool/call method, the StructuredContent parameter does not exist in the returned result. The parameter is nil：

Debug found that in the ParseCallToolResult of CallTool, there was no operation to parse StructuredContent and assign a value. In the returned result, StructuredContent was nil, which caused this problem.

Code Sample

my mcp-server code:

my mcp-client code:

maybe the problem code in mcp-go 0.36.0

Logs or Error Messages

Environment

• Go version (see go.mod): 1.23
• mcp-go version (see go.mod): 0.36.0
• Any other relevant environment details: Centos 7.5

Possible Solution

when i add resutl.StructuredContent = jsonContent["StructuredContent"] in utils.ParseCallToolResultParseCallToolResult, it will solve this problem