There are plenty of agent list sites. Set some parameters and press Search to see every agent in the game that fits. Those did not work for me so I made my own.
EVEMissioneer.com is an agent finder / explorer. Free; no ads; hosted in UK; HTTPS (DigiCert SSL). Live (in this incarnation) since November 2021.
Set your filters using option in top bar. Change filter any time, for example level 1 and 2 basic security agents in hi-sec but not Minmatar regions. Filter is applied to all corporations, regions and constellations. Systems use the filter plus surrounding systems within 3 jumps. Most agent lists are grouped by region. Filter; explore; click click click.
Regions, constellations and systems have links to DOTLAN and zKillboard. Almost all corporations (with an LP store) have a link to Ellathra LP database.
Faction does not use filter because it has special lists: level 5s, data centers, etc. COSMOS agent mission names were taken from the quality EVE Special Agents Toolkit by YariLei.
It is optional to connect your pilot with SSO to import standings and diplomacy/connections skills (thanks to the excellent Burberius EVE-ESI API). Agent, corporation and faction standings will now be shown on the relevant pages. And a new column will show for each agent if they are available now or how much standing you need to unlock them.
For connected pilot, the standings summary presents information in a sane order (IMHO compared to the game client). It is up to you when you next update your standings but minimum is one hour. After you update you can see the new list including an option to show only the standings that changed.
Connected pilots can choose to ignore agents from any region, constellation or system. Look for the white or red magnifier icon at the top of their pages. I do not care for Solitude for example.
EVEMissioneer.com is built for the way I want to find agents. It may not be suitable for you but it is another tool in the toolbox. No responsibility is taken by me for in-game deaths caused by using the site. Or out-of-game for that matter. Be sensible.
Constructive feedback welcomed.