[Bug]: Custom tool inputSchema has empty properties

[JerryNixon]

Custom tools

AI agents cannot discover parameter names or types for custom tools from the schema. They must rely on the description text or describe_entities.

desired

"inputSchema": {
  "type": "object",
  "properties": {
    "productId": { "type": "integer" }
  },
  "required": [ "productId" ]
}

actual

The inputSchema for custom tools has "properties": {} or empty. No parameter information is exposed.

{
  "name": "reassign_todo",
  "description": "Reassigns a todo item to a different user",
  "inputSchema": { "type": "object", "properties": {} }
}