What it does, in a few words, for HELP and the reference.
OptionalcapLimits what an agent can spend or send.
OptionalenvRead from the environment only, on purpose: no flag or tool argument can set it.
The HELP section it is listed under.
The variable's name.
OptionalsecretHolds a secret: keep it out of files, logs and the model's context.
One entry in ENV_VARS.