[Bug] Claude Sonnet refuses to generate network monitoring code

**Bug Description**
Sonnet refused to write the network monitoring code it insisted I needed to debug the network stream corruption we've been getting on GCP compute instances.

**Environment Info**
- Platform: darwin
- Terminal: Apple_Terminal
- Version: 2.1.238
- Feedback ID: d2493922-0aa5-4e98-b6ab-9dd3ced34899

**Errors**
```json
[{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: {\"type\":\"error\",\"error\":{\"type\":\"permission_error\",\"message\":\"MCP server returned 403 Forbidden. The request may have been blocked by a firewall or security service.\",\"details\":{\"error_code\":\"mcp_request_blocked\"}},\"request_id\":\"req_011CeQ7QBqh4W7irLrpDWdqr\"}\n at send (/$bunfs/root/cli:3105:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-25T20:38:33.511Z"},{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: {\"type\":\"error\",\"error\":{\"type\":\"permission_error\",\"message\":\"MCP server returned 403 Forbidden. The request may have been blocked by a firewall or security service.\",\"details\":{\"error_code\":\"mcp_request_blocked\"}},\"request_id\":\"req_011CeQ7Qdpe2inKMCPFHVCKG\"}\n at send (/$bunfs/root/cli:3105:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-25T20:38:39.577Z"},{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: {\"id\":2,\"jsonrpc\":\"2.0\",\"result\":{\"content\":[{\"text\":\"Request had insufficient authentication scopes.\",\"type\":\"text\"}],\"isError\":true}}\r\n at send (/$bunfs/root/cli:3105:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-25T20:39:49.721Z"},{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: {\"type\":\"error\",\"error\":{\"type\":\"permission_error\",\"message\":\"MCP server returned 403 Forbidden. The request may have been blocked by a firewall or security service.\",\"details\":{\"error_code\":\"mcp_request_blocked\"}},\"request_id\":\"req_011CeQ7WgW38qb5JjN7oHkxd\"}\n at send (/$bunfs/root/cli:3105:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-25T20:40:01.559Z"},{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: {\"id\":5,\"jsonrpc\":\"2.0\",\"result\":{\"content\":[{\"text\":\"Request had insufficient authentication scopes.\",\"type\":\"text\"}],\"isError\":true}}\r\n at send (/$bunfs/root/cli:3105:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-25T20:52:29.669Z"},{"error":"Error: Streamable HTTP error: Error POSTing to endpoint: {\"id\":6,\"jsonrpc\":\"2.0\",\"result\":{\"content\":[{\"text\":\"Request had insufficient authentication scopes.\",\"type\":\"text\"}],\"isError\":true}}\r\n at send (/$bunfs/root/cli:3105:6002)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-08-25T20:52:47.423Z"}]
```

No source file, test, or entry point is named. Start by reproducing the reported MCP Streamable HTTP requests and compare the refusal with the logged 403 and insufficient-scope responses. Done requires identifying whether Claude Code has a client-side failure to address or whether the block is external to the project.

Written by the indexing model from the issue text.