Should a history book written as a narrative be disregarded as a source? Recently, I found several sources relevant to my research paper, and also written by prominent historians, but the book is written in first person, in some narrative form, with dialogue added. I find it a little strange, because the text has complete conversations, that I think could not possibly be recorded in such detail.
When I studied my BA in History, there was a course that discussed in detail how to evaluate a source, against the CRAAP test and other similar measures, yet I'm not sure where this fails the checklist:

Currency
Relevance
Authority
Accuracy
Purpose

My colleagues keep recommending me such texts to use. Are these types of texts something I should skip over when writing a research paper?
[T]he book is written in first person, in some narrative form, with dialogue added. I find it a little strange, because the text has complete conversations, that I think could not possibly be recorded in such detail.

The author may have recreated dialogue, rather than definitely sourced dialogue. Perhaps look for an author's note, disclaimer, or similar, to see whether techniques are disclosed.

Should a history book written as a narrative be disregarded as a source? Are these types of texts something I should skip over when writing a research paper?

Use sources you believe to be accurate. When there's doubt, sources needn't be abandoned, caution can be taken to absolve responsibility for prior errors, e.g., Author X provides the following account, &quot;...&quot;.