Claude Desktop generates fake files instead of using available MCP tools

[Wolfe-Jam]

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Discussion Topic

Hey Anthropic MCP team,

Flagging a model behavior issue: When users request file creation, Claude Desktop
generates fake files with fabricated content in container paths and offers
downloads, rather than calling available MCP tools that would create accurate
files in the user's actual project directory.

What's happening:

• User is creating a new project.faf file locally
• Desktop generates fake project.faf in /web container with made-up content →
  offers download
• User downloads it to their project directory
• File contains fabricated data (wrong tech stack, incorrect structure, fictional
  context)
• AI later reads this fake context and gives wrong suggestions
• MCP tool available: faf_init (scans actual project, creates accurate file in
  correct location)

Impact:
Users unknowingly operate with fabricated project context. Desktop creates
convincingly wrong output instead of using MCP to generate correct output from
actual project analysis.

Core question:
Why is Claude Desktop behaving like Claude.ai? Users install Desktop specifically
for MCP integration. If the model defaults to web behavior (container files,
fabricated content), what's the differentiator?

Workaround:
We've built Projects convention path resolution and guide tools to work around
this, but ideally this should be a global model fix benefiting all MCP servers.

Related issues: #2410, #1016, #1520

Ask:
Could the model be prompted to default to MCP tools for file operations when
available? This would leverage Desktop's core differentiator and prevent fake
file generation across the MCP ecosystem.

Happy to provide session transcripts or fake vs. real file comparisons if
helpful.

Thanks for building MCP!

[olaservo]

Hi @Wolfe-Jam , I don't think that Claude Desktop support is monitoring these discussions - I would take a look at the support options here instead: https://support.claude.com/en/articles/9015913-how-to-get-support