[EricH]

Well, only one Minibot can be used on a Hostbot at a time, so they can only use one at a time. Other than that, no restrictions that I can think of.

Now, tools and materials: There are restrictions other than the weight limit, but only on tools (and the weight limit only applies to Fabricated Items).

If you look at the Administrative Manual, Section 3, there are restrictions on tools/work that you can have/use/do in the pits. Often, it's "go to designated area away from pits" (grinding, painting, stuff like that). Other times, it's "Go to the machine shop". You are allowed benchtop tools, but nothing larger (no floor-based drill presses, say). They're a little extensive to list fully, so here's the short version:

--Is it floor-based? Leave it at home if it is.
--Is it going to throw sparks or produce hazardous fumes or get on someone else's robot, even unintentionally? Check the Admin Manual, but you will probably need to work with those outside the pit area.
--If you answered "no" to both questions above, bring it if you think you might possibly need it. If you don't, someone else probably will.