fix(athena): provider-aware config + better council error messages

Use parsed.providerID/modelID in council member description instead of
raw model string (eliminates dead variable). Track skipped members with
reasons and surface them in the missing-council guard prompt so users
see why their council failed to register.

src/agents/builtin-agents.ts

@@ -203,8 +203,8 @@ export async function createBuiltinAgents(
     result["atlas"] = atlasConfig
   }
 
-  if (councilConfig && councilConfig.members.length >= 2 && result["athena"]) {
+  if (councilConfig?.members && councilConfig.members.length >= 2 && result["athena"]) {
-    const { agents: councilAgents, registeredKeys } = registerCouncilMemberAgents(councilConfig)
+    const { agents: councilAgents, registeredKeys, skippedMembers } = registerCouncilMemberAgents(councilConfig)
     for (const [key, config] of Object.entries(councilAgents)) {
       result[key] = config
     }
@@ -217,9 +217,9 @@ export async function createBuiltinAgents(
         prompt: (result["athena"].prompt ?? "") + councilTaskInstructions,
       }
     } else {
-      result["athena"] = appendMissingCouncilPrompt(result["athena"])
+      result["athena"] = appendMissingCouncilPrompt(result["athena"], skippedMembers)
     }
-  } else if (councilConfig && councilConfig.members.length >= 2 && !result["athena"]) {
+  } else if (councilConfig?.members && councilConfig.members.length >= 2 && !result["athena"]) {
     log("[builtin-agents] Skipping council member registration — Athena is disabled")
   } else if (result["athena"]) {
     result["athena"] = appendMissingCouncilPrompt(result["athena"])

src/agents/builtin-agents/athena-council-guard.ts

@@ -42,9 +42,16 @@ After informing the user, **end your turn**. Do NOT try to work around this by u
  * Replaces Athena's prompt with a guard that tells the user to configure council members.
  * Used when Athena is registered but no valid council config exists.
  */
-export function appendMissingCouncilPrompt(athenaConfig: AgentConfig): AgentConfig {
+export function appendMissingCouncilPrompt(
-  return {
+  athenaConfig: AgentConfig,
-    ...athenaConfig,
+  skippedMembers?: Array<{ name: string; reason: string }>,
-    prompt: (athenaConfig.prompt ?? "") + MISSING_COUNCIL_PROMPT,
+): AgentConfig {
+  let prompt = (athenaConfig.prompt ?? "") + MISSING_COUNCIL_PROMPT
+
+  if (skippedMembers && skippedMembers.length > 0) {
+    const skipDetails = skippedMembers.map((m) => `- **${m.name}**: ${m.reason}`).join("\n")
+    prompt += `\n\n### Why Council Failed\n\nThe following members were skipped:\n${skipDetails}`
   }
+
+  return { ...athenaConfig, prompt }
 }

src/agents/builtin-agents/council-member-agents.ts

@@ -19,25 +19,33 @@ function getCouncilMemberAgentKey(member: CouncilMemberConfig): string {
  * Each member becomes a separate agent callable via task(subagent_type="Council: <name>").
  * Returns a record of agent keys to configs and the list of registered keys.
  */
+type SkippedMember = { name: string; reason: string }
+
 export function registerCouncilMemberAgents(
   councilConfig: CouncilConfig
-): { agents: Record<string, AgentConfig>; registeredKeys: string[] } {
+): { agents: Record<string, AgentConfig>; registeredKeys: string[]; skippedMembers: SkippedMember[] } {
   const agents: Record<string, AgentConfig> = {}
   const registeredKeys: string[] = []
+  const skippedMembers: SkippedMember[] = []
 
   for (const member of councilConfig.members) {
     const parsed = parseModelString(member.model)
     if (!parsed) {
+      skippedMembers.push({
+        name: member.name,
+        reason: `Invalid model format: '${member.model}' (expected 'provider/model-id')`,
+      })
       log("[council-member-agents] Skipping member with invalid model", { model: member.model })
       continue
     }
 
     const key = getCouncilMemberAgentKey(member)
-    const config = createCouncilMemberAgent(member.model)
-
-    const description = `Council member: ${member.name} (${member.model}). Independent read-only code analyst for Athena council. (OhMyOpenCode)`
 
     if (agents[key]) {
+      skippedMembers.push({
+        name: member.name,
+        reason: `Duplicate name: '${member.name}' already registered`,
+      })
       log("[council-member-agents] Skipping duplicate council member name", {
         name: member.name,
         model: member.model,
@@ -46,6 +54,9 @@ export function registerCouncilMemberAgents(
       continue
     }
 
+    const config = createCouncilMemberAgent(member.model)
+    const description = `Council member: ${member.name} (${parsed.providerID}/${parsed.modelID}). Independent read-only code analyst for Athena council. (OhMyOpenCode)`
+
     agents[key] = {
       ...config,
       description,
@@ -65,8 +76,8 @@ export function registerCouncilMemberAgents(
 
   if (registeredKeys.length < 2) {
     log("[council-member-agents] Fewer than 2 valid council members after model parsing — disabling council mode")
-    return { agents: {}, registeredKeys: [] }
+    return { agents: {}, registeredKeys: [], skippedMembers }
   }
 
-  return { agents, registeredKeys }
+  return { agents, registeredKeys, skippedMembers }
 }