Suggestion for the tag-info, in case we decide to keep the tag. (I made the post CW, feel free to make any reasonable improvements.)
Tag-excerpt:
For questions about Chebyshev functions $\vartheta(x)$ and $\psi(x)$, which are often used in number theory. For questions about Chebyshev polynomials, use the (chebyshev-polynomials) tag.
Tag-wiki:
This tag is intended for questions about Chebyshev functions $\vartheta(x)$ and $\psi(x)$, which are often used in number theory. These functions are defined as $$\vartheta(x)=\sum_{p\le x} \log p$$ and $$\psi(x) = \sum_{p^k\le x}\log p=\sum_{n \leq x} \Lambda(n) = \sum_{p\le x}\lfloor\log_p x\rfloor\log p.$$
For questions about Chebyshev polynomials, use the (chebyshev-polynomials) tag.
