mcp-repl is a REPL client, not a production tool server. The 9 tools in examples/mcp_repl_fixture.rs are test fixtures for demonstrating the client's capabilities, not real-world tools. Tool descriptions are minimal (10-50 chars), parameter descriptions are absent, and schemas lack detail. Most tools have no documented output structure. This is appropriate for a fixture but would fail production standards. The server itself (tower-mcp 0.22.1, protocol-2026-07-28) is well-maintained, but the fixture tools are intentionally sparse.

• Rename 'tool' and 'builtin' to action-verb names (e.g., 'demo_tool', 'test_builtin') that reflect their test purpose.
• Expand all descriptions to 50-150 chars explaining WHAT each tool does and WHEN to call it (e.g., 'add: Adds two integers and returns their sum. Use for arithmetic operations in test scenarios.').
• Add parameter descriptions for 'a' and 'b' in add/wait/slow_add (e.g., 'a: First integer operand', 'b: Second integer operand').
• Document output schemas for all tools (e.g., add returns {"type": "object", "properties": {"result": {"type": "integer"}}})
• Add error handling guidance to fail/fail_slowly descriptions (e.g., 'fail: Intentionally returns an MCP error for testing error recovery paths.').

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry