AI Agent adding period after URL

We have an issue where the AI Agent is adding a Period after the URL despite having a prompt not to do so. The prompt that we have for this is: Do not append any characters or trailing Periods (.) at the end of any of URLs provided in tools

We have some document tools attached where we provide some external links. The document does not include a period at the end of the URL. It does a good job retrieving the entire URL, but it just adds a full stop at the end. This results in the period being included in the hyperlink and breaking it. I am looking for some guidance on the best way to correct this.