Tagging APIs is important for discovery of APIs across the API lifecycle. The tags applied at the API level should reflect the business value provided, and leave other technical details to when OpenAPI tagging is applied–balancing both the business and technical cataloging of API resources and capabilities.
All tags applied to APIs are ideally part of a larger vocabulary and taxonomy used across API operations, developed as part of wider governance efforts. API tags should employ both nouns and verbs to description the business value present across a group of paths and operations organized via one or many OpenAPIs.
Take the time to tag your APIs. Don’t take any shortcuts, and make sure they accurately describe everything that is possible. Do the work to align your API tags with your OpenAPI tags–this is part of the wider work to align the business and technical sides of your API operations, so make sure you work on alignment.