Fix code quality issues in LiteRT-LM MCP server

[Copilot]

Addresses code review feedback on the LiteRT-LM MCP server implementation: unused imports, dead code, indentation inconsistencies, missing input validation, and error handling gaps.

Changes

Code cleanup:

• Removed unused subprocess import
• Removed dead try-except block with empty pass statement
• Fixed indentation inconsistencies (4-space standard)

Input validation & security:

• Added prompt validation (non-empty string check)
• Added runtime backend parameter validation against allowed values ["cpu", "gpu", "npu"]

# Validate prompt parameter
if not prompt or not isinstance(prompt, str) or not prompt.strip():
    return {"status": "error", "message": "Invalid or empty prompt..."}

# Validate backend parameter
valid_backends = ["cpu", "gpu", "npu"]
if backend not in valid_backends:
    return {"status": "error", "message": f"Invalid backend '{backend}'..."}

Error handling robustness:

• Added try-except for write pipe connection failures with fallback to stdout
• Set writer = None on drain errors to prevent repeated failures

Documentation:

• Updated README example from multimodal (unsupported) to text-only inference
• Added note clarifying CLI wrapper limitations

Consistency:

• Aligned Windows handling pattern with other MCP servers (cloudflare_server, code_analysis_server)
• Standardized logging to f-strings

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Project	Deployment	Review	Updated (UTC)
event-relay-web	Error		Jan 29, 2026 5:29pm
v0-uvai	Error		Jan 29, 2026 5:29pm

[Copilot]

Pull request overview

This PR refines the LiteRT-LM MCP server by cleaning up unused/dead code, tightening input validation, hardening error handling around subprocess and stdio, and aligning the README with the current text-only CLI capabilities.

Changes:

• Added explicit validation for prompt and backend arguments, returning structured error responses for invalid input.
• Simplified and clarified I/O handling in the main loop, including safer writer drain handling and a consistent fallback to sys.stdout.write.
• Updated README usage example and documentation to reflect text-only support and clarify multimodal limitations for the CLI wrapper.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
mcp-servers/litert-mcp/server.py	Cleans up unused code, adds prompt/backend validation, and hardens async stdio writing/drain error handling for more robust MCP request processing.
mcp-servers/litert-mcp/README.md	Updates the run_inference example and notes to emphasize text-only inference and clarify multimodal limitations of the current CLI wrapper.