Open
Description
If the function signature contains a variable of ToolContext type not named "tool_context" the agent fails with a user-unfriendly exception like "ValueError: Failed to parse the parameter ctx: google.adk.tools.tool_context.ToolContext of function ...".
Ideally, the function should take any variable name and provide the context when called. At the very least, it should indicate that renaming the variable will solve the problem.