agent-mail — the multi-agent coordination domain

Purpose: one owner for how sessions coexist on a shared checkout — identity, file
reservations, teardown, build slots. The MCP server provides the tools
(mcp__mcp-agent-mail__*); this skill owns the doctrine and procedure for using them.

The two-minute version

1. Mint a Tier-1 identity at session start if you will reserve files or commit under
   your own name; capture name + registration_token and pass both on EVERY call, reads
   included (references/session-procedure.md § Mint, § Export).
2. Reserve the files you are about to edit, at the work grain, BEFORE editing
   (§ Reserve). On FILE_RESERVATION_CONFLICT: skip or re-plan — never claim over it.
3. Release + self-deregister as your true last act (§ Release) — own name only,
   never retire_agent, never cross-session, never FoggyCreek.
4. FoggyCreek is the shared Tier-2 chore identity — it may commit chore files but
   may NEVER claim beads or reserve files
   (references/agent-identity.md § Tier 2).

References (the domain canon)

• references/session-procedure.md — the CALL
  PROCEDURE: mint template, the two call-scoped facts (explicit token threading;
  per-shell AGENT_NAME re-assert), export block, reservation cycle, release/deregister
  exit ordering.
• references/agent-identity.md — the DOCTRINE: the
  two-tier contract (minted Tier-1 vs FoggyCreek Tier-2), the three deregistration
  layers + ac-ycr.8 runtime facts, assignee-vs-reservation split, enforcement layers
  (pre-commit guard), canonical project-key format.

Related mechanisms (owned elsewhere, used with these tools)

• Pre-commit reservation guard install: install_precommit_guard — invoked in
  ac-implement Phase 0; blocks commits touching another agent's reserved paths.
• Build slots (advisory, always-grant): usage pattern in the batch boundary's § Build Slot;
  memory agent-mail-build-slot-advisory.
• Child-spawn contract (children usually hold NO Agent Mail tools — conductor reserves
  on their behalf): ac-pipeline/references/delegation-contract.md.