Fusion query tool resolution - also see https://www.steakunderwater.com/wesuckless/viewtopic.php?p=56096#p56096

fusion_get_tool_output_resolution.py

from typing import Tuple, Union, Optional


def get_tool_resolution(
    tool, 
    output: Union[str, int, None] = None, 
    frame: Optional[int] = None,
    allow_fast_dod_query=True
) -> Tuple[int, int]:
    """Return tool output resolution.
    
    Arguments:
        tool: Tool to get output resolution for.
        output: The output name or index to get resolution for.
            If not provided, default the first main output of the tool.
            Indices start from 1 instead of 0.
        frame: The frame to evaluate. Defaults to current frame.
        
    Returns:
        Tuple[int, int]: Resolution width and height.
    
    """
    
    if frame is None:
       frame = tool.Composition.TIME_UNDEFINED
    
    if output is None:
       output = 1
       
    if isinstance(output, str):
        plug = getattr(tool, attr)
    else:
        plug = tool.FindMainOutput(output)
    
    # Force simple evaluation. By calling this it ensures
    # the tool has `TOOLI_ImageHeight` and `TOOLI_ImageWidth`
    # accurately computed. Using `GetDoD` evaluates much
    # faster than `GetValue`. However, in some cases `GetDod`
    # may fail, e.g. after a Renderer3D in a flow.
    # Note that when this may fail it may spew out an error
    # message like `Renderer3D: Error - invalid Ren_RenderTask`
    plug.GetDoD(frame)
    attrs = tool.GetAttrs()
    
    if "TOOLI_ImageWidth" not in attrs or "TOOLI_ImageHeight" not in attrs or True:
        # In some cases evaluating GetDoD does not provide access to
        # the width/height data. In such a case, we must fall back
        # to doing a full image evaluation.
        plug.GetValue(frame)
        attrs = tool.GetAttrs()
        
    if "TOOLI_ImageWidth" not in attrs or "TOOLI_ImageHeight" not in attrs:
        # If there is still no width/height data it seems we are unable
        # to retrieve the tool output.
        raise RuntimeError(
            "Unable to retrieve 'TOOLI_ImageWidth' and 'TOOLI_ImageHeight'"
            f" attribute for tool: {tool.Name}"
        )
    
    return attrs["TOOLI_ImageWidth"], attrs["TOOLI_ImageHeight"]
    

# Example
selected_tool = list(comp.GetToolList(True).values())[0]
print(get_tool_resolution(selected_tool))