DiffGate provides 4 read-only code search and analysis tools with basic JSON Schema input definitions. All tools have descriptions and documented parameters, but descriptions are minimal (10-30 chars) and lack LLM optimization. Parameter descriptions are present but sparse. No output schemas are documented. Error handling guidance is absent. The tool set is well-named (verb_noun convention) and properly scoped, but lacks the depth and completeness expected of production agent tools. STDIO-only transport limits overall utility despite reasonable tool definitions.

• Expand all tool descriptions to 50 - 150 characters. Include WHAT the tool does, WHEN to call it, and WHAT it returns. Example: 'Search repository with extended regex. Returns matching files and line numbers. Use for pattern discovery; slower than find_references for symbol lookups. Returns up to 100 matches; use filters for large results.'
• Document output schemas for all tools. Specify fields (file_path, line_number, match_text, author, commit_hash, etc.) and types so LLMs can plan chaining calls and extract relevant data.
• Add error classification to tool implementations. Return structured errors: '{error: "invalid_regex", message: "Invalid regex syntax: unmatched parenthesis. Escape special characters or use -F for literal strings.", retryable: false}' instead of stack traces.
• Enhance parameter descriptions with format and constraint details. Example for grep pattern: 'Extended regex pattern (POSIX ERE). Use -E flag escaping rules. Max 1000 chars.' Example for find_references symbol: 'Identifier to search (whole-word match, case-sensitive). Max 256 chars.'
• Add result limiting and pagination hints. Document that grep and find_references cap results at a reasonable limit (suggest 50 - 100) and provide guidance on refining filters or using offset/limit if pagination is implemented.
• Implement schema validation in tool handlers. Validate regex syntax before executing grep; validate file paths against repo boundaries in read_file to prevent path traversal.
• Consider documenting tool idempotency. All four tools are read-only and safe to retry, but explicit confirmation in tool annotations or descriptions clarifies this to agent planners.