[Bug] Anthropic API Error: Tool Result Block Missing Corresponding Tool Use Block

Resolved 💬 2 comments Opened Jun 5, 2026 by amElnagdy Closed Jun 9, 2026

Bug Description
API Error: 400 messages.3.content.0: unexpected tool_use_id found in advisor_tool_result blocks: srvtoolu_01Wr57BkH7X8heLDrtN9y9JD. Each advisor_tool_result block must have a corresponding server_tool_use block before it.

Environment Info

  • Platform: darwin
  • Terminal: vscode
  • Version: 2.1.165
  • Feedback ID: af4a57e3-308d-4471-8a62-d3fa3491a693

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01Wr57BkH7X8heLDrtN9y9JD. Each `advisor_tool_result` block must have a corresponding `server_tool_use` block before it.\"},\"request_id\":\"req_011CbkhqTaJwBKZwhmp9dqQC\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:65689)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-06-05T19:58:38.136Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01Wr57BkH7X8heLDrtN9y9JD. Each `advisor_tool_result` block must have a corresponding `server_tool_use` block before it.\"},\"request_id\":\"req_011CbkhtZCjKPtTNudZ1oZ34\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:65689)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-06-05T19:59:20.166Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01Wr57BkH7X8heLDrtN9y9JD. Each `advisor_tool_result` block must have a corresponding `server_tool_use` block before it.\"},\"request_id\":\"req_011CbkjXUxPPCK6sgxHa5gyJ\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:65689)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-06-05T20:20:48.006Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01Wr57BkH7X8heLDrtN9y9JD. Each `advisor_tool_result` block must have a corresponding `server_tool_use` block before it.\"},\"request_id\":\"req_011CbkjXigtV2WAv1Uxx1QBA\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:65689)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-06-05T20:20:51.115Z"}]

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