fix: added missing schema/validation

Author: nickytonline

pkg/github/projects.go

@@ -629,7 +629,24 @@ func UpdateProjectItem(getClient GetClientFn, t translations.TranslationHelperFu
 			mcp.WithString("owner", mcp.Required(), mcp.Description("If owner_type == user it is the handle for the GitHub user account. If owner_type == org it is the name of the organization. The name is not case sensitive.")),
 			mcp.WithNumber("project_number", mcp.Required(), mcp.Description("The project's number.")),
 			mcp.WithNumber("item_id", mcp.Required(), mcp.Description("The numeric ID of the project item to update (not the issue or pull request ID).")),
-			mcp.WithArray("fields", mcp.Required(), mcp.Description("A list of field updates to apply.")),
+			mcp.WithArray("fields", mcp.Required(), mcp.Description("A list of field updates to apply."),
+				mcp.Items(
+					map[string]interface{}{
+						"type":                 "object",
+						"additionalProperties": false,
+						"required":             []string{"field_id", "value"},
+						"properties": map[string]interface{}{
+							"field_id": map[string]interface{}{
+								"type":        "string",
+								"description": "The ID of the field to update",
+							},
+							"value": map[string]interface{}{
+								"description": "The value to set for the field",
+							},
+						},
+					},
+				),
+			),
 		), func(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 			owner, err := RequiredParam[string](req, "owner")
 			if err != nil {

pkg/github/tools_validation_test.go

@@ -0,0 +1,58 @@
+package github
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/github/github-mcp-server/pkg/translations"
+	"github.com/stretchr/testify/require"
+)
+
+// TestAllArrayParametersHaveItems verifies that all array-type tool parameters
+// have an "items" schema defined, which is required by OpenAI's API
+func TestAllArrayParametersHaveItems(t *testing.T) {
+	translator, _ := translations.TranslationHelper()
+
+	// Get all tools from toolsets
+	toolsetGroup := DefaultToolsetGroup(false, nil, nil, nil, translator, 500)
+
+	// Enable all toolsets to get all tools
+	_ = toolsetGroup.EnableToolsets([]string{"all"})
+
+	for _, toolset := range toolsetGroup.Toolsets {
+		for _, serverTool := range toolset.GetAvailableTools() {
+			toolName := serverTool.Tool.Name
+			inputSchema := serverTool.Tool.InputSchema
+
+			// Marshal to JSON to inspect the schema
+			schemaJSON, err := json.Marshal(inputSchema)
+			require.NoError(t, err, "failed to marshal schema for tool %s", toolName)
+
+			var schema map[string]interface{}
+			err = json.Unmarshal(schemaJSON, &schema)
+			require.NoError(t, err, "failed to unmarshal schema for tool %s", toolName)
+
+			// Check properties
+			properties, ok := schema["properties"].(map[string]interface{})
+			if !ok {
+				continue // No properties, skip
+			}
+
+			for propName, propValue := range properties {
+				propDef, ok := propValue.(map[string]interface{})
+				if !ok {
+					continue
+				}
+
+				// If this is an array type, it MUST have an "items" property
+				if propType, hasType := propDef["type"].(string); hasType && propType == "array" {
+					_, hasItems := propDef["items"]
+					require.True(t, hasItems,
+						"tool %s has array parameter %s without 'items' schema definition. "+
+							"OpenAI requires all array parameters to have an 'items' schema.",
+						toolName, propName)
+				}
+			}
+		}
+	}
+}