Summary
Returns a count of the parameter values for the specified tool. If the tool is contained in a custom toolbox, use ImportToolbox to access the custom tool.
Syntax
GetParameterCount (tool_name)
| Parameter | Explanation | Data Type | 
tool_name  | The name of the tool for which the number of parameters will be returned.  | String | 
Return Value
| Data Type | Explanation | 
| Integer | The number of parameters for the specified tool.  | 
Code sample
GetParameterCount example
Returns the number of tool parameters.
import arcpy
# Returns 7
print(arcpy.GetParameterCount("Buffer_analysis"))