如果用户提供的函数没有description，就应该明确报错，不让他继续使用 (#273)

Fixes #271

Author: chenxizhang

code365scripts.openai/Private/Functions.ps1

@@ -17,6 +17,19 @@ function Get-FunctionJson {
 
     # generate a json object based on the help content of the function
     $help = Get-Help $functionName
+
+    # if the help doesn't include description, return null
+    if (-not $help.description) {
+        Write-Warning "Function $functionName does not have a description."
+        return $null
+    }
+
+    # if any parameters don't include description, return null
+    if ($help.parameters.parameter | Where-Object { -not $_.description }) {
+        Write-Warning "Function $functionName has parameters without description."
+        return $null
+    }
+
     $json = [pscustomobject]@{
         type     = "function"
         function = @{

code365scripts.openai/Public/New-ChatGPTConversation.ps1

@@ -296,9 +296,8 @@ function New-ChatGPTConversation {
         if ($functions) {
             $tools = @(Get-PredefinedFunctions -names $functions)
 
-            Write-Verbose  ($tools | ConvertTo-Json -Depth 10)
-
             if ($tools.Count -gt 0) {
+                Write-Verbose  ($tools | ConvertTo-Json -Depth 10)
                 if ($null -eq $config) {
                     $config = @{}
                 }