Passing dynamic Flow Variables to Agent Tools without relying on LLM arguments

Hi everyone,

I am building an agentic automation workflow where an LLM Agent orchestrates several tools. The process involves iterating through a list of documents, where the Agent calls a tool to perform complex processing on a specific file stored on KNIME Hub. Due to the nature of the file for it to be accessed it needs to be copied over into the tool’s data folder for it to be processed.

The Problem: I need to pass the dynamic file path (which changes every loop iteration) from the Main Workflow into the Tool Workflow.

Currently, I am achieving this by injecting the file path into the System Prompt (e.g., “You are processing file: [Path]. When you call the processing tool, pass this path as the ‘input_file’ argument”).

Why this is not ideal: This relies on the LLM “remembering” to copy-paste the string correctly into the tool’s function call. This introduces a risk of hallucination or typos, especially with complex paths.

My Question: Is there a robust, deterministic way to pass a Flow Variable from the Main Workflow directly into the Tool Workflow’s configuration without making it a parameter that the LLM has to generate?

Has anyone successfully implemented a pattern for “Global Context” or “Dynamic Tool Configuration” to handle this?

If not can we have a feature request to pass flow variables from parent workflows into tool workflows.