Attenu AI agents increasingly delegate tasks to other agents. Each delegation should convey only a subset of the delegating party's authority, that subset should be bounded in scope, magnitude, and time, and any enforcement point should be able to verify -- offline, with no call to an authorization server -- that a token presented at hop N carries authority no greater than the token at hop N-1, back to a trusted root, and that every hop acts under the same accountable principal. OAuth 2.0 Token Exchange (RFC 8693) models two-party delegation and records prior actors in a nested "act" claim, but that claim is informational only and cannot enforce attenuation across a chain of depth two or more. This document defines the Agent Delegation Chain: a profile of OAuth 2.0 JWT access tokens (RFC 9068) that carries authority as Rich Authorization Requests (RFC 9396), binds the chain to one principal and names the agent acting at each hop, links each delegation to its parent by a cryptographic byte- commitment, and specifies a deterministic offline verification algorithm that enforces monotonic attenuation, bounded depth, monotonic expiry, and principal invariance. It reuses existing JOSE, proof-of-possession (RFC 9449), and status-list machinery (the OAuth Status List draft) and introduces no new cryptography.