QUOTE: “The score is determined from quantities indicating user actions of seeking out and preferring particular sites and the resources found in particular sites. *****A site quality score for a particular site**** can be determined by computing a ratio of a numerator that represents user interest in the site as reflected in user queries directed to the site and a denominator that represents user interest in the resources found in the site as responses to queries of all kinds The site quality score for a site can be used as a signal to rank resources, or to rank search results that identify resources, that are found in one site relative to resources found in another site.” Navneet Panda, Google, 2015
Experience can educate you when a page is high-quality and yet receives no traffic. If the page is thin, but is not manipulative, is indeed ‘unique’ and delivers on a purpose with little obvious detectable reason to mark it down, then you can say it is a high-quality page – just with very little search demand for it. Ignored content is not the same as ‘toxic’ content.
QUOTE: “Important: The Lowest rating is appropriate if all or almost all of the MC (main content) on the page is copied with little or no time, effort, expertise, manual curation, or added value for users. Such pages should be rated Lowest, even if the page assigns credit for the content to another source.” – Google Search Quality Evaluator Guidelines 2019
Having a different description meta tag for each page helps both users and Google, especially in searches where users may bring up multiple pages on your domain (for example, searches using the site: operator). If your site has thousands or even millions of pages, hand-crafting description meta tags probably isn't feasible. In this case, you could automatically generate description meta tags based on each page's content.
QUOTE: “The purpose of a page is the reason or reasons why the page was created. Every page on the Internet is created for a purpose, or for multiple purposes. Most pages are created to be helpful for users, thus having a beneficial purpose. Some pages are created merely to make money, with little or no effort to help users. Some pages are even created to cause harm to users. The first step in understanding a page is figuring out its purpose.” Google Search Quality Evaluator Guidelines 2019
QUOTE: “The average duration metric for the particular group of resources can be a statistical measure computed from a data set of measurements of a length of time that elapses between a time that a given user clicks on a search result included in a search results web page that identifies a resource in the particular group of resources and a time that the given user navigates back to the search results web page. …Thus, the user experience can be improved because search results higher in the presentation order will better match the user’s informational needs.” High Quality Search Results based on Repeat Clicks and Visit Duration
In Keyword Planner, formerly known as the Keyword Tool, you can get search volume and traffic estimates for keywords you're considering. Unfortunately, when Google transitioned from Keyword Tool to Keyword Planner, they stripped out a lot of the more interesting functionality. But you can make up for it a bit if you take the information you learn from Keyword Planner and use Google Trends to fill in some blanks.
Ask for explanations if something is unclear. If an SEO creates deceptive or misleading content on your behalf, such as doorway pages or "throwaway" domains, your site could be removed entirely from Google's index. Ultimately, you are responsible for the actions of any companies you hire, so it's best to be sure you know exactly how they intend to "help" you. If an SEO has FTP access to your server, they should be willing to explain all the changes they are making to your site.