Bug: External ACP agents (e.g. Fred) fail delegation — missing `role` in agent.md

[aj47]

Summary

Delegating to external ACP agents like Fred fails with "agent not found" because their agent.md frontmatter is missing role: delegation-target, causing them to be excluded from the delegation lookup path.

Root Cause

Fred's ~/.agents/agents/286c6b41-.../agent.md has this frontmatter:

---
connection-type: acp
name: Fred
displayName: Fred
enabled: true
id: 286c6b41-28ed-4a57-9728-0bab9846ebe6
kind: agent
---

Missing field: role: delegation-target

How the lookup chain works:

1. handleDelegateToAgent() → calls agentProfileService.getByName(agentName) (line 587 of acp-router-tools.ts)
2. getByName() searches this.profilesData.profiles — finds Fred ✅
3. BUT handleListAvailableAgents() → calls getEnabledAgentTargets() → calls getAgentTargets() → calls getByRole("delegation-target") (line 652 of agent-profile-service.ts)
4. getByRole("delegation-target") filters profiles where p.role === "delegation-target" OR legacy fallback p.isAgentTarget === true
5. assembleAgentProfile() in agents-files/agent-profiles.ts (line 250) sets: isAgentTarget: mdPartial.role === "delegation-target" || mdPartial.role === "external-agent" || undefined
6. Since Fred has no role in frontmatter → role = undefined → isAgentTarget = undefined → Fred is excluded from agent targets

The inconsistency:

• getByName("Fred") in handleDelegateToAgent DOES find Fred (it searches all profiles)
• getEnabledAgentTargets() in handleListAvailableAgents DOES NOT include Fred (filtered out by role)
• The system prompt's "AVAILABLE AGENTS" section uses getByRole('delegation-target') (line 176 of system-prompts.ts) — should also exclude Fred

So delegation to Fred may actually work via getByName() → executeAgentProfileDelegation(), but Fred won't appear in list_available_agents or the system prompt's agent list unless role is set.

Fix Options

Option A: Fix agent.md (quick fix)

Add role: delegation-target to Fred's frontmatter. This is the user-level fix.

Option B: Auto-infer role for ACP/stdio/remote agents (proper fix)

In assembleAgentProfile() (agents-files/agent-profiles.ts ~line 230), if role is not set but connection.type is acp, stdio, or remote, auto-assign:

role: mdPartial.role ?? (connectionType !== 'internal' ? 'delegation-target' : undefined),
isAgentTarget: mdPartial.role === "delegation-target" || mdPartial.role === "external-agent" || connectionType !== 'internal' || undefined,

Option C: Fix the agent creation flow

When creating an agent with connection-type: acp, the creation code should auto-set role: delegation-target. Check builtin-tools.ts:1472 where this already happens for some paths but may not cover all creation flows.

Files Involved

File	Line	What it does
agents-files/agent-profiles.ts	250	assembleAgentProfile — sets isAgentTarget based on role
agents-files/agent-profiles.ts	200	parseAgentProfileMarkdown — parses role from frontmatter
agent-profile-service.ts	611-631	getByRole — filters by role/isAgentTarget
agent-profile-service.ts	650-657	getAgentTargets — combines role + legacy lookups
agent-profile-service.ts	522-527	getByName — searches all profiles (no role filter)
acp-router-tools.ts	587	handleDelegateToAgent — uses getByName (works)
acp-router-tools.ts	482	handleListAvailableAgents — uses getEnabledAgentTargets (broken)
system-prompts.ts	176	Builds AVAILABLE AGENTS section — uses getByRole (broken)

Reproduction

1. Create an external ACP agent (connection-type: acp) without explicitly setting role: delegation-target in agent.md
2. Agent won't appear in list_available_agents output
3. Agent won't appear in system prompt's AVAILABLE AGENTS section
4. Direct delegation via delegate_to_agent may still work (uses getByName which searches all profiles)