tool name naming policy changed on preview3

[vongzh]

Is your feature request related to a problem? Please describe.
The tool calls the DeriveName(MethodInfo method, JsonNamingPolicy? policy = null) function during name serialization. It is expected to use the JsonNamingPolicy defined in the options as the parameter, but currently this parameter is null.

[stephentoub]

Are you saying it changed between preview2 and preview3? It shouldn't have. This change was introduced in #568 in preview 2, by design, as described in the PR. The implementation now defaults to lower_snake_case to match the conventions used by the rest of the mcp ecosystem. That policy parameter on the internal helper is there in case we want to tweak this further.

[vongzh]

Are you saying it changed between preview2 and preview3? It shouldn't have. This change was introduced in #568 in preview 2, by design, as described in the PR. The implementation now defaults to lower_snake_case to match the conventions used by the rest of the mcp ecosystem. That policy parameter on the internal helper is there in case we want to tweak this further.

Apologies — I skipped a few versions and mistakenly thought this change was introduced in a newer release. Thanks for your patience and clarification.I initially assumed the JsonNamingPolicy from options would flow into the internal DeriveName method, but I see now it's deliberately defaulting to lower_snake_case for MCP consistency. Makes sense now!

Do you plan to allow external override of the naming policy in future, or is it expected that we should always follow the established convention?

[stephentoub]

No worries.

You can already override it on a tool by tool basis, just by specifying the Name you want to use, either in the [McpServerTool] if you're using attributes, or via the arguments to McpServerTool.Create if you're using it programmatically. We don't currently intend to expose a global override, but could if there's enough interest.

[vongzh]

No worries.  不用担心。

You can already override it on a tool by tool basis, just by specifying the Name you want to use, either in the [McpServerTool] if you're using attributes, or via the arguments to McpServerTool.Create if you're using it programmatically. We don't currently intend to expose a global override, but could if there's enough interest.您已经可以逐个工具地覆盖它了，只需指定您想要使用的名称，如果您使用属性，可以在[McpServerTool]中指定，如果您是编程方式使用，则可以通过 McpServerTool.Create 的参数来指定。我们目前没有打算提供一个全局覆盖，但如果兴趣足够，我们可以提供。

Got it, thanks for the clear explanation! Really appreciate it!

[vongzh]

change my useage