Indentation & Glossary

Question

I am working on a book and I want to include a glossary at the end of it. I face a couple of issues:

1. It seems that the glossary has a left margin (see the distance compared to the "Glossary" title). I show the frame on the MWE.
2. I would like to indent each description compared to their name (but keep the fact the my whole book has no indentation as shown on MWE)
3. I don't think that the way the page are displayed after the description is clear. Can I add something like "..." before the number ? or put a row of dots and the page number on the right?

Does anyone know how solve any of these points?

MWE:

\documentclass{book}
\usepackage[showframe]{geometry}

\usepackage[xindy,toc,acronym,nopostdot]{glossaries} %TOC = in table of content, xindy = indexation tool, needs to be BEFORE HYPERLINK
\setglossarystyle{altlist}
\renewcommand{\glsgroupskip}{}
\makeglossaries

\usepackage{enumitem}
\setlist[enumerate]{topsep=3pt,itemsep=1pt,partopsep=0ex,parsep=0ex}
\setlist[itemize]{topsep=3pt,itemsep=1pt,partopsep=0ex,parsep=0ex}
\setlist[description]{topsep=3pt,itemsep=2pt,partopsep=0ex,parsep=0ex,leftmargin=15pt,labelindent=15pt}
\parindent 0in
\parskip 0.05in
\setlength{\textfloatsep}{0.8\baselineskip plus 0.2\baselineskip minus 0.2\baselineskip}

\newglossaryentry{Alpha}
{ name=Alpha,
  description={Smoothing factor applied to the demand level in the various exponential smoothing models. In theory: \ensuremath{ 0 < \alpha \leq 1}, in practice: \ensuremath{0 < \alpha \leq 0.6}}}
\newglossaryentry{Beta}
{ name=Beta,
  description={Smoothing factor applied to the trend in the various exponential smoothing models. In theory: \ensuremath{ 0 < \beta \leq 1}, in practice: \ensuremath{0 < \beta \leq 0.6}}}
\newglossaryentry{Gamma}
{ name=Gamma,
  description={Smoothing factor applied to the seasonality (either additive or multiplicative) in the triple exponential smoothing models. In theory: \ensuremath{ 0 < \gamma \leq 1}, in  practice: \ensuremath{0.05 < \gamma \leq 0.3}}}
\newglossaryentry{Phi}
{ name=Phi,
  description={Damping factor applied to the trend in the exponential smoothing models. This reduces the trend after each period. In theory: \ensuremath{ 0 < \phi \leq 1}, in practice: \ensuremath{0.7 \leq \phi \leq 1}}}
\begin{document}
\glsaddall
\printglossary
\end{document}

Answer 1

You can redefine theglossary to pass a optional argument to desciption:

\renewenvironment{theglossary}{%
  \begin{description}[style=standard,labelindent=0pt]%
}{\end{description}}

The command \glspostdescription controls what iis inserted between the description and the pagenumber, to fill with dots use

\renewcommand\glspostdescription{\dotfill}

This results in

\documentclass{book}
\usepackage[showframe]{geometry}

\usepackage[xindy,toc,acronym,nopostdot]{glossaries} %TOC = in table of content, xindy = indexation tool, needs to be BEFORE HYPERLINK
\setglossarystyle{altlist}%
\renewenvironment{theglossary}{%
  \begin{description}[style=standard,labelindent=0pt]%
}{\end{description}}
\renewcommand\glspostdescription{\dotfill}
\makeglossaries

\usepackage{enumitem}
\setlist[enumerate]{topsep=3pt,itemsep=1pt,partopsep=0ex,parsep=0ex}
\setlist[itemize]{topsep=3pt,itemsep=1pt,partopsep=0ex,parsep=0ex}
\setlist[description]{topsep=3pt,itemsep=2pt,partopsep=0ex,parsep=0ex,leftmargin=15pt,labelindent=15pt}
\parindent 0in
\parskip 0.05in
\setlength{\textfloatsep}{0.8\baselineskip plus 0.2\baselineskip minus 0.2\baselineskip}

\newglossaryentry{Alpha}
{ name=Alpha,
  description={Smoothing factor applied to the demand level in the various exponential smoothing models. In theory: \ensuremath{ 0 < \alpha \leq 1}, in practice: \ensuremath{0 < \alpha \leq 0.6}}}
\newglossaryentry{Beta}
{ name=Beta,
  description={Smoothing factor applied to the trend in the various exponential smoothing models. In theory: \ensuremath{ 0 < \beta \leq 1}, in practice: \ensuremath{0 < \beta \leq 0.6}}}
\newglossaryentry{Gamma}
{ name=Gamma,
  description={Smoothing factor applied to the seasonality (either additive or multiplicative) in the triple exponential smoothing models. In theory: \ensuremath{ 0 < \gamma \leq 1}, in  practice: \ensuremath{0.05 < \gamma \leq 0.3}}}
\newglossaryentry{Phi}
{ name=Phi,
  description={Damping factor applied to the trend in the exponential smoothing models. This reduces the trend after each period. In theory: \ensuremath{ 0 < \phi \leq 1}, in practice: \ensuremath{0.7 \leq \phi \leq 1}}}
\begin{document}
\glsaddall
\printglossary
\end{document}