Fix tool schema compatibility with OpenAI models

[edcdavid]

OpenAI models require the "properties" field to be present in the JSON schema for tool input, even when a tool takes no parameters. Add an empty properties map to the configuration_contexts_list and targets_list tool schemas to ensure compatibility.

Assisted by: Cursor

[manusa]

Hi @edcdavid, thx for getting involved.
This is not a proper fix.
The toolset definition gets transformed in a latter stage at the MCP domain layer, so whatever you change here, doesn't mean that it will be sent to the MCP client and host.

This issue (#717) was already fixed, first in this repository, and later in the go-sdk directly.

We have specific tests to ensure that this is the case:

kubernetes-mcp-server/pkg/mcp/toolsets_test.go

Lines 195 to 225 in b371f49

	// https://github.com/containers/kubernetes-mcp-server/issues/717
	// Verifies ALL tools have Properties initialized (not just cluster-aware ones)
	// OpenAI API requires properties field even if empty
	s.Run("InputSchema has properties for all tools regardless of cluster-awareness", func() {
	// Register all toolsets including kcp to catch kcp_workspaces_list
	toolsets.Clear()
	toolsets.Register(&core.Toolset{})
	toolsets.Register(&config.Toolset{})
	toolsets.Register(&helm.Toolset{})
	toolsets.Register(&kcp.Toolset{})
	s.Cfg.Toolsets = []string{"core", "config", "helm", "kcp"}
	// Enable multi-cluster mode to include configuration_contexts_list tool
	kubeconfig := s.Kubeconfig()
	kubeconfig.Contexts["extra-cluster"] = clientcmdapi.NewContext()
	s.Cfg.KubeConfig = test.KubeconfigFile(s.T(), kubeconfig)
	s.InitMcpClient()
	tools, err := s.ListTools()
	s.Require().NoError(err, "Expected no error from ListTools")
	s.Require().NotNil(tools, "Expected tools from ListTools")
	s.Require().NotEmpty(tools.Tools, "Expected at least one tool")
	// Check each tool has InputSchema.properties initialized
	for _, tool := range tools.Tools {
	s.Run(tool.Name, func() {
	schema, ok := tool.InputSchema.(map[string]any)
	s.Require().True(ok, "Expected InputSchema to be map[string]any for tool %s", tool.Name)
	s.Require().NotNil(schema["properties"],
	"Expected InputSchema.properties not to be nil for tool %s (required by OpenAI API)",
	tool.Name)
	})
	}
	})

Are you using the latest version of the server.

If you are, and are still facing the issue, try to provide a reproducer first.