1. A computer program product for providing completion support and on demand validation in a web tool that operates on live resources, the computer program product comprising: one or more computer readable storage devices and program instructions stored on the one or more computer readable storage devices, wherein the computer readable storage device is not a transitory signal per se, the stored program instructions comprising: program instructions to create one or more lists of content, wherein the one or more lists of content include one or more references to one or more runtime objects, and wherein content in the one or more lists of content includes one or more elements of a uniform resource identifier; program instructions to parse the one or more lists of content, wherein parsing the one or more lists of content includes determining a name of at least one of the one or more runtime objects; program instructions to populate one or more lists of one or more choices with the parsed one or more lists of content; program instructions to create one or more callbacks for one or more runtime objects referenced by the one or more lists of one or more choices; program instructions to display the one or more lists of one or more choices; program instructions to build a dependency tree that includes at least one of the one or more runtime objects referenced by the one or more lists of content; program instructions to receive a notification of a change to one or more of the referenced one or more runtime objects, wherein program instructions to receive a notification of a change to one or more of the referenced one or more runtime objects results from creation of the one or more callbacks; program instructions to run a validation against the one or more changed referenced one or more runtime objects; program instructions to determine whether one or more of the one or more changed referenced one or more runtime objects is invalid; responsive to determining one or more of the one or more changed referenced one or more runtime objects is invalid, program instructions to mark the invalid changed referenced one or more runtime objects; program instructions to output results of the validation; and program instructions to apply one or more types of one or more filters to the one or more lists of content, wherein one or more types of one or more filters includes at least one of a type filter and a predicate filter.