This server implements 4 file operations with basic tool definitions. Strengths: all tools have descriptions (10-34 chars), input schemas are present with typed properties, and tool annotations (readOnlyHint, destructiveHint) are correctly applied. Critical gaps: descriptions are extremely terse (well below the 194-char baseline for production tools), completely missing any output schema documentation, no parameter constraints (e.g., path format, allowed characters), no error recovery guidance, and no security boundary documentation despite exposing destructive operations (deleteFile, writeFile). The tool set is single-concern and reasonably named (verb_noun pattern), but the definitions lack the depth needed for confident agent reasoning. Error handling exists but returns generic McpError with minimal context, LLMs cannot distinguish retryable from fatal failures or know what to do next.
Tool descriptions are critically terse (10-34 chars, well below 194-char production baseline). They lack context on WHEN to use each tool, prerequisites, or expected return structure. LLMs cannot reliably select tools or understand their semantics.
No output schema documented for any tool. Callers cannot know what fields to expect or plan downstream tool chaining. E.g., listDirectory response structure is completely opaque.
deleteFile and writeFile are destructive but lack dry-run/confirmation or any warning mechanism. No guidance on consequences or recovery. Agents have no way to prevent accidental data loss.
deleteFilewriteFile
HIGH
Recommendations
Expand tool descriptions to 80-150 characters each. Example for readFile: 'Read a file from the filesystem. Returns the file content as text. Use for accessing configuration, logs, or data files. Returns error if path does not exist or is not readable.'
Add detailed path parameter constraint: 'Path to a file or directory (string, 1-4096 chars, no null bytes). Supports both relative and absolute paths. Cannot traverse outside configured root directory (e.g., no ../../../etc).'
Add error recovery guidance. When path not found, suggest: 'File not found: /path/to/file. Try calling listDirectory to see available files.' For permission denied: 'Access denied to /path/to/file. Check permissions or try a different directory.'
For deleteFile, add a confirmation pattern: introduce a 'confirm_delete' boolean parameter (default false, must be explicitly true). Or require a tool like preview_file_deletion that shows what would be deleted before the actual delete.
Error responses are generic (McpError with minimal context). No recovery guidance for common failures (file not found, permission denied, path traversal attempts). LLM cannot self-correct or decide whether to retry.
The 'path' parameter lacks any validation constraints or format description. No guidance on allowed characters, max length, or whether relative vs absolute paths are supported. No mention of symlink handling or path traversal guards.
No permission model or access control documented. Users cannot understand which paths are readable/writable or how the server enforces boundaries. Destructive tools (deleteFile, writeFile) have no authorization checks mentioned.
listDirectory has no pagination or result limit. Large directories could produce responses that exhaust context window or timeout. Missing limit, offset/cursor, and total_count fields.
readFile returns content as a plain string with no metadata (file size, encoding, MIME type, modified time). Agents cannot reason about binary files or plan caching/truncation.
readFile
Document security boundaries: 'This server can read/write only within the configured filesystem root. Paths outside this root are rejected. The server does not follow symlinks to prevent escape attacks.'
Add readOnlyHint correctly to listDirectory (already present for readFile) and mark destructiveHint on both deleteFile and writeFile (already done). Consider adding idempotentHint=true for readFile and listDirectory since they have no side effects.
For readFile, add file size limits: 'Returns error if file exceeds 100 MB. Large files can be read in chunks by calling readFile with offset/limit parameters.' (if chunking is supported). If not, cap returns and document the limit.
Add audit/logging guidance in tool descriptions or server documentation: 'All file operations are logged with timestamp, operation type (read/write/delete), path, and outcome. Destructive operations require user confirmation.'