Address Claude review follow-ups

packages/agent-loop/src/loop.ts

@@ -502,6 +502,11 @@ async function runStep(
   if (stepError) throw stepError
 
   if (assembler.finish.kind === 'max-tokens') {
+    let message: Message = withoutToolCalls(assembler.message())
+    message = withoutToolCalls(await ctx.waterfall('agent/step-result', agent, turn, step, message, () => Promise.resolve(message)))
+    if (message.content.length > 0) {
+      session.append('assistant/message', { turn, step, content: message.content })
+    }
     if (assembler.usage) {
       session.append('usage', { turn, step, usage: assembler.usage })
     }
@@ -566,6 +571,10 @@ async function runStep(
   return { hadToolCalls: toolCalls.length > 0, finish: assembler.finish }
 }
 
+function withoutToolCalls(message: Message): Message {
+  return { ...message, content: message.content.filter(block => block.type !== 'tool-call') }
+}
+
 /** The last turn number in a (possibly seeded) session log, or 0. */
 export function lastTurnNumber(session: Session): number {
   const lastStart = session.events.findLast(event => event.type === 'turn/start')

packages/agent-loop/tests/loop.spec.ts

@@ -385,6 +385,10 @@ describe('agent loop', () => {
 
     expect(steps).toBe(2)
     expect(adapter.requests).toHaveLength(2)
+    expect(adapter.requests[1]!.messages).toEqual([
+      { role: 'user', content: [{ type: 'text', text: 'go' }] },
+      { role: 'assistant', content: [{ type: 'text', text: 'first half' }] },
+    ])
     expect(reasons).toEqual([{ kind: 'max-tokens' }])
   })
 
@@ -436,10 +440,38 @@ describe('agent loop', () => {
 
     expect(executions).toBe(0)
     expect(agent.session.events.some(e => e.type === 'tool/call')).toBe(false)
+    expect(agent.session.deriveMessages()).toEqual([{ role: 'user', content: [{ type: 'text', text: 'go' }] }])
+    expect(reasons).toEqual([{ kind: 'max-tokens' }])
+  })
+
+  it('keeps safe max-tokens assistant content while dropping truncated tool calls', async () => {
+    const callId = CallId('c1')
+    const adapter = new MockAdapter([[
+      { type: 'block-start', index: 0, blockType: 'text' },
+      { type: 'text-delta', index: 0, text: 'partial text' },
+      { type: 'block-end', index: 0, block: { type: 'text', text: 'partial text' } },
+      { type: 'block-start', index: 1, blockType: 'tool-call' },
+      { type: 'tool-call-delta', index: 1, id: callId, name: 'echo', argumentsDelta: '{"text"' },
+      { type: 'finish', reason: { kind: 'max-tokens' } },
+    ]])
+    const ctx = await harness(adapter)
+    let stepResults = 0
+    ctx.on('agent/step-result', async (_agent, _turn, _step, message, next) => {
+      stepResults += 1
+      expect(message.content).toEqual([{ type: 'text', text: 'partial text' }])
+      return next()
+    })
+    const agent = ctx.agentLoop.create('a1', { model: 'mock' })
+
+    send(agent, 'go')
+    await waitForIdle(ctx, agent)
+
+    expect(stepResults).toBe(1)
+    expect(agent.session.events.some(e => e.type === 'tool/call')).toBe(false)
     expect(agent.session.deriveMessages()).toEqual([
       { role: 'user', content: [{ type: 'text', text: 'go' }] },
+      { role: 'assistant', content: [{ type: 'text', text: 'partial text' }] },
     ])
-    expect(reasons).toEqual([{ kind: 'max-tokens' }])
   })
 
   it('stops the turn when agent/step-end listener failure has recorded an error', async () => {