UC-016

UC-016: Hidden/Extra Args in Tool Call

Layer: B — Dispatch Enforcement Threat: Tool Misuse / Parameter Injection

Scenario

A tool call includes valid declared arguments plus additional undeclared fields that could influence downstream behavior.

Expected Behavior

  • Extra fields in tool call args → DENY
  • Deny-on-unknown-fields enforced at schema PEP
  • Signed deny receipt produced

Pass Criteria

  • Verdict: DENY
  • Extra fields rejected, not silently ignored
  • Receipt: signed with full ArgsHash