Minecraft wiki entry for attribute, associated text: attribute <target> <attribute> get [<scale>]
Returns the total value of the specified attribute.
attribute <target> <attribute> base get [<scale>]
Returns the base value of the specified attribute.
attribute <target> <attribute> base set <value>
Overwrites the base value of the specified attribute with the given value.
attribute <target> <attribute> modifier add <uuid> <name> <value> (add|multiply|multiply_base)
Adds an attribute modifier with the specified properties if no modifier with the same UUID already existed.
attribute <target> <attribute> modifier remove <uuid>
Removes the attribute modifier with the specified UUID.
attribute <target> <attribute> modifier value get <uuid> [<scale>]
Returns the value of the modifier with the specified UUID.