Game-making requires tools. This obviously includes game engines (because your game needs to work in order to be called a game), but there are many other tools that we can and do use. Map editors, metadata editors, sound effect generators, Paint.NET, and so on.
Obviously some tools are more exclusively related to game-making than others. Let's focus on those.
What do you want from your tools? Which features do you find useful, and which can you live without? Which features would you like to have? What do you think of the tools you've used? Why did you choose to use them, and were there alternatives you rejected?
I suspect the majority of responses will be about RPG Maker XP and what you think about it, and that's fine. Try not to talk about Pokémon Essentials, though, as I don't think that's a tool (I'd call it a resource).
Well I personally think Editor.exe is a pointless tool, I don't use it, only to do connections (only because I'm not sure how they "connect", otherwise I wouldn't bother at all). I prefer to be in complete control, knowing what I'm adding, where I'm adding it to and why I'm adding it, not just adding things because an outside editor tells me to (not specifically aimed at Essentials editor).
I like RMXP though, since it does everything I want and I still haven't used all it's features... But things like being able to control an NPC is high on my list of features I like, there's nothing I hate more than playing an RPG and only being 1 character... RMXP also allows me to make people say what I want them to say, act how I want them to act, that's always fun, giving NPC's characteristics.
Using painting programs is a must from me too, as I said, I like full control of what I'm using and if a picture doesn't look right, I will make it look right, sometimes... After all, your game can't be your game if everything was made by someone else... I hate when you check out a game and everything that makes their game look good, is made by someone else and being used whether they had permission or not, games like that get ignored by me, so I kind of hope that something I make gets acknowledged for what it is, unique.
Flexibility. Like Nickalooose said, I want to be in full control of the tool that I'm using. So if it is an engine I'm making my game with, I want to be able to change every single stock engine/mechanism. Whether it is through changing the code, or by other means. I like to be able to alter and expand upon even the basic of functions. By having full control, pretty much everything needs to be changeable. From the game window, to the map system, to the battle system and so on.
One of the things I dislike about RMXP is how inflexible it is when it comes to the RGSS Player, and window itself. For instance, it took complex Win32API coding for a basic change like this (resizing the window and removing the border contents). Everybody has different visions on how they want their game to be played. So the input methods used would need to be flexible as well. On top of that, if the game is for the PC, I'd expect full native support of all the inputs available on the PC (mouse and keyboard). Perhaps some methods to control the sound and the general environment of the engine would be nice. Lol, what I'd do is look at everything RMXP doesn't allow you to do, and then have that.
The major thing to consider would be people with no experience with the tool. You'd probably want to make it as user-friendly as possible, without removing the ability to manually change the stuff. So I don't really know how that would pan out. I'd personally look for being able to do precise, manual changes. One that require looking for, and knowledge. A nice code structure and support would also be preferable, with a language in the centre that is powerful. RGSS is nice, but it is slow, and lags with the more requiring functions. C# is more difficult, but makes up for it with its wast capabilities and performance.
Probably, the most important "feature" of the tool: detailed documentation. The tool really needs to be able to display what it can do, and how to do it. That's a lot of work to do, but for it to be really efficient, every little thing should be documented. That way, everybody would have somewhere to start off. Perhaps sample "events" and "codes" should be made, to help further convey the functions the tool is offering.
A tool is there to make the life of the game developer easier. And IMO the best tools for RMXP are the ones that generate graphics for you without you being involved with it that much. When i say graphics, i especially think of "Overworlds" and maybe "Facesets". Think of a Character generator that can generate hundreds of individual overworlds within minutes just by using templates like these:
There are already attempts to make one for RMXP but they have their flaws and aren't specialized on Pokemon games. Here is the best one i could find. A Character generator is really an helpful tool to save a lot of work and it makes your game more individual. But many people are needed to rip or make enough templates that the generator can use. If enough people are interested maybe it can become a community project. I am not that optimistic thought. However here are the HGSS Overworlds. And just because i showed some Gen 4 templates it is not restricted to it. It is easy to generate Gen 3 and Gen 5 overworlds as well as long as you have the templates. But i guess you guys figured that out already.
Ahh yeah i mentioned facesets as well. This one is not as easy because RMXP doesn't support facesets on default and therefor there is no one that made a generator for it. So we need some scripts to implement that into RMXP (and Essentials) first. I know there are some scripts somewhere on the internet but i think it should work with Essentials as well. Here is the best faceset generator i could find. It is easy to work with and you can make any kind of face with a little knowledge of image editing tools. It is a .psd file so Photoshop is usefull but not necessary. You could use this .psd plug-in for the free program "paint.net" and use it instead.
It is obvious that an advanced game needs advanced and individual graphics. A graphic generator can make your life much easier in that point and people with no graphical skills get easy access to many different and good quality overworlds/facesets. So it will effectively rise the optical charm of many games .
I, personally, specifically look for only free and open source (GPL v2 for the win) tools because they're flexible, and, well, open source. I like things that run on GNU/Linux (without the use of Wine), so that is always a plus. I look on GitHub for most of my stuffs.
For game design, I've been looking at possibly forking this pure C game engine called Corange. It's lesser known, but it works like a charm and it's pure C. I love C. C++, which most game engines are written in, is rather mediocre, whereas C is beautiful and flexible. However, admittedly, OOPS often does do the job better than standard database-driven languages like C.
Altogether, what I look for in a tool is this: CONTROL and FREEDOM (and C).
My philosophy also is, if the tool I want isn't out there, I'll make it. Which reminds me: I keep meaning to get some more work done on my torrent cleint. Hrmf. Work.
Good point about Editor.exe, Nickalooose. That definitely counts as a tool. While it provides useful options, it feels a bit clunky to use, and I also prefer editing PBS files directly if possible because there's a definite clean feeling of knowing exactly what you're doing (even if you can make mistakes).
I can only really talk about RMXP, because it's the only tool I've had much experience with. I think it's a great program, and you could do a lot worse than it. VX Ace (which I recently briefly tried out) is better in some respects, and worse in others.
RMXP has some distinct shortcomings, though. One is a lack of map error detection, usually introduced when a tileset or map is changed (e.g. pointing to a tile which no longer exists, map transfers to maps/coordinates which no longer exist, etc.) or some Database value is altered somehow. I'd like to see a button which checks for all this and informs the user of problems (with the option to ignore/erase/set to default depending on the error).
Another useful feature, particularly for collaborative work, would be the ability to import individual maps and, to a lesser extent, import/export individual tilesets.
Then there's the limited 3 layers, 7 autotiles, fiddly higher-number terrain tags stuff, of course, along with needing to use PBS files rather than the built-in Database (which is otherwise a great feature).
A feature that would be useful in a Pokémon engine's map editor is the inclusion of event templates. Rather than inserting a blank event, you could add a filled-in event instead (for a trainer, a door, an item ball, etc.).
A tool should definitely be easy to use, which is achieved through a well-designed GUI and good documentation/help labels.
Ctrl+F and Ctrl+Z are vital to me, I prefer to do somethings on text editor rather that at a graphical editor because of these two (and Find/Replace).
For me, the most important thing in a game engine are the resources and tutorials avaliables, specially a non-commercial one because this make the game-making more practical. FOR ME, I liked alot when RPG Maker 2k/2k3 trade some event features for script use in RPG Maker XP since this make very more pratical an option screen for example, plus the several scripts avaliable in the web. I know that this is a step backward in easiness that's the RPG Maker focus, but for me is better, even knowing about some 2k/3 plugins like Destiny Patch.
Basically, a beginner dev wants easiness and a advanced dev wants control, performance (with some exceptions) and practicality (except the stranges devs who want to tries to make something like a platform game in a RPG engine, I can't understand these cases).
Talking about RPG Maker, I want a option to handle the imported musics loops, something to speed up the door/stairs making a two way stair for a point only clicking in a second point (with template options), the script code to be compiled (like Unity) before th game starts to raise performance and more Ctrl+F options for search about resources and text. I like alot the RPG Maker XP Script Editor Ctrl+Shift+F feature. For some reasons this is more practical (quicker and shows the information that I need) that the others similar tools that I tried.
The Essentials translation tool is a very useful tool even if you won't going to translate, because this extract the game text and make easier to search about something!
Find and Replace are VERY useful in some text editors if you know how to use it.
In Paint.NET I use alot of Magic Wand and Hue.
I also love professionals IDEs like netbeans and Eclipse. The autocomplete, corrections suggestions, links to declarations/methods, highlight the variables that I select, auto imports are AMAZING. I strong suggest these tools for anyone who uses Java/C#.