Mandatory-read guards and prior art: UCON obligations, optimistic concurrency and AgentCore temporal policies
Requiring a prior read is not new: it is a UCON pre-obligation (2004), and AgentCore's documentation expresses it. No reviewed work documents a service-held current version plus a fresh engine-side read of the action's object.
Prediction heldBetter than simpler options?Working note
- Designed for
- Desk study of the guard's required-read rule: which parts are covered by UCON obligations, optimistic concurrency control and AWS AgentCore temporal policies, and what may honestly be claimed as new.
What was tested
The guard’s required-read rule demands that the session has read the current version of an applicable document, with applicability read from the action’s own object. On 2026-11-02 we set it against UCON_ABC, XACML 3.0, Thor-style optimistic concurrency, AWS Bedrock AgentCore Policy and agent-guard papers such as CaMeL and FIDES, marking how each source was checked.
What we observed
The rule is a special case of the UCON_ABC pre-obligation (Park and Sandhu, 2004) with an XACML-style policy information point. Optimistic concurrency cannot see objects that were never read. Per its documentation, AgentCore temporal policies can require a prior read in the session, but not the version the service holds as current, nor a fresh read of the action’s object by the engine, except by rewriting the policy at each amendment. No reviewed work combines both.
What this means for Heimdall
This asks whether prior work covers the required read, not whether it works: the rule is a UCON-style pre-obligation, not a new mechanism.
Limits
Several sources were read by abstract only; vendor pages were not archived; AgentCore’s custom providers are undocumented. “No reviewed work” is bounded by the search.
What remains open
Read every source in full on the publication date.