This is not a problem specific to tags.
Someone can always make an unclear question. They can do it with words in the title, words in the question or words in the tags. The site response to lack of clarity is, I trust, well trod enough not to require me to go over it. Get them to clarify, vote to close if needed.
Tags do convey implicit information, which is why they exist, have tag wikis, etc. It's good, and a useful shorthand. If someone wants a system-agnostic technique they don't need to spend a paragraph explaining "I want a technique I can use across the various games I run, man". I can only imagine most attempts at doing this would lead to even more pedantic arguing in comments.
This is a long way to go for a pretty simple answer.
For example, game system tags are pretty self explanatory. If it says [dnd-5e] then it can be assumed to be a normal D&D 5e question. Some uses of tags are clear.
However, just adding a tag sometimes doesn't really give enough information, or at least is going to create bad answers. "Give me a way to alternate melee and ranged attacks" simply tagged with [feat] isn't going to sufficiently signal to an answerer that you only want feats as an answer to the question. This use of a tag is unclear.
If your question is not clear - make it clear, using tags, words in the body, words in the title, etc.
If you do not understand a question - including its tag use - ask for clarification. It's the actual intended, constructive use of the comment system. Trying to somehow change how everyone intuitively uses tags is not practical or desirable.