I usually put very minimal information for my own package seeds. I love randomness and surprises, but for long distance sharing is different, maybe more information is relevant for the next grower. Usually I write on paper and put inside a small saleable bag.
1- Generation. I always put the number of generations that I have grown the seed. If the generation is low is a new crop, usually the seed is precious and I do not have much. If the number is high, the seed is better adapted but can have more inbreeding.
If a seed is from my great grandmother and is planted regularly every year on the same plot, should I put generation 100+?. Where do I come from?
2- Number of seeds. Usually I do not care for small seeds, but I do not know how much is too much. Maybe 100 squash seeds is a lifetime of seeds for my comrade and for me is just the first planting.
How many squash should I share? How many I am?
3- Hardiness zone. Usually this information is the same for all the seeds that I saved, but maybe is relevant for sharing seeds. Maybe zone 5 summer seeds can be grown in zone 10 in winter. Where do I live?
4- Climate. Dry, wet, windy. Maybe if grown in greenhouses or carried inside in winter.
Where do the seeds feel cozy?
5- Conditions of the soil. Type of soil, clay, calcisol, sandy, rocky or just in raised beds full of compost. Type of irrigation, drip lines or sprinklers. Grown between weeds, wood chips or in plastic tarps. I do not do supplements, but probably fertilizers should be here.
What is my diet and plate?
I try to keep it minimal: common name, botanical name if the former might cause confusion, date seed harvested, parentage if relevant, generation if relevant. That’s it.
As for number of seeds, that’s quite variable - anywhere from 5 to 50 or even more, depending on seed size and how many I had spare.
For the serendipity seedpack I put my initials so people can check my growing blog for this year to get idea of the climate. They can google location and compare weather statistics. I think that’s enough for your list 3-5. Each growing season is different no matter where you are and most places have similar seasons at some points of the growing season. Point 1 is maybe most important, but that also relies on people receiving seeds to know how different species behave. Like if there is a bean variety you can be almost certain it’s true to type even it’s been grown for many generations promiscuously, but if it’s cucurbita then you would know there are crosses. Then knowing how many generations would be helpful. If the seeds are segregating then you wouldn’t need to know that much more. Some are likely to work in most places if applied to season that best suits their origin.
I put the species name and the year of harvest. If it’s a bulk bottle it might have several years on it. If I have several different phenotypes of a species, I’ll also add the phenotype. “Medium maxima, 2022,2023”.
If people want more information that that, they can ask.
Location. I’ll consider putting my name or initials on there in the future. I can see how that is useful so you know who to ask if you want further information.