Summer of Protocols

"The purpose of a system is what it does" :: "The purpose of a protocol is what it _______"?

I work for Ethereum at the Ethereum Foundation.

One of the interesting ideas (see Olivia essay) from SoP was that protocols do not have purposes. Only functions.

Blogger at ribbonfarm.com, running summerofprotocols.com, host of /gloom ☀️

“Disposition” might be a good word. In Extrastatecraft, Keller Easterling argues that urban planning and building protocols have mechanistic “dispositions” (such as homogenization)

then maybe: 

"The purpose of a system is what it does" :: "The ________ of a protocol is what it does"?