Dynamically add meta description based on route in Angular

First create a SEOService or Something like below:

import {Injectable} from '@angular/core'; 
import { Meta, Title } from '@angular/platform-browser';

@Injectable({
  provideIn: 'root' // Add this to ensure your SEO service will be app-wide available
})
export class SEOService {
  constructor(private title: Title, private meta: Meta) { }


  updateTitle(title: string) {
    this.title.setTitle(title);
  }

  updateOgUrl(url: string) {
    this.meta.updateTag({ name: 'og:url', content: url })
  }

  updateDescription(desc: string) {
    this.meta.updateTag({ name: 'description', content: desc })
  }
}

After injecting the SEOService in your component (app.component.ts preferably), set meta tags and title in OnInit method

ngOnInit() {
    this.router.events.pipe(
       filter((event) => event instanceof NavigationEnd),
       map(() => this.activatedRoute),
       map((route) => {
         while (route.firstChild) route = route.firstChild;
         return route;
       }),
       filter((route) => route.outlet === 'primary'),
       mergeMap((route) => route.data)
      )
      .subscribe((event) => {
        this._seoService.updateTitle(event['title']);
        this._seoService.updateOgUrl(event['ogUrl']);
        //Updating Description tag dynamically with title
        this._seoService.updateDescription(event['title'] + event['description'])
      }); 
    }

Then configure your routes like

      { 
        path: 'about', 
        component: AboutComponent,
        data: {
          title: 'About',
          description:'Description Meta Tag Content',
          ogUrl: 'your og url'
        } 
      },

IMHO this is a clear way of dealing with meta tags. You can update facebook and twitter specific tags easier.