Single tool with adequate but not exemplary definition. Tool name 'translate_ja_to_en' follows verb_noun convention and is clear. Description is present (227 chars, within 10-1024 range) and explains WHAT the tool does and WHEN to use it. However, the description could be more concise for LLM token efficiency. Input schema is minimal, single 'text' parameter with a string type and basic description ('The Japanese text to translate.'). Parameter description is only 31 chars and lacks guidance on expected format, length constraints, or edge cases (e.g., max text length, handling of mixed Japanese/English input). Output schema is not documented, the function returns a string, but LLMs cannot see what fields they should expect or how to chain subsequent operations. No error recovery guidance provided: when translation fails due to configuration, network, or API errors, the tool returns generic messages like 'Translation failed due to a configuration issue' without actionable next steps (e.g., 'Check server environment variables' or 'Retry with exponential backoff'). Error categorization is implicit in the code (ValueError, HTTPStatusError, RequestError, generic Exception) but not exposed in the tool contract. Tool is READ_ONLY (no state mutation), which is correct. No tool annotations (readOnlyHint, destructiveHint, idempotentHint) are present in the fastMCP decorator, these should be explicit. Overall, the tool is functional and follows basic patterns, but lacks the depth of description and error guidance expected of production-grade tools.

• Expand input parameter description from 31 chars to 80-120 chars. Include format, length constraints, and edge case guidance: 'The Japanese text to translate (1 - 5000 characters, UTF-8 encoded). May contain hiragana, katakana, kanji, and punctuation. Returns error if text is empty or exceeds 5000 chars.'
• Document the output schema explicitly in the tool description or return type annotation. Clarify that the tool returns a plain English text string (no metadata wrapper). Example: 'Returns: str, the translated English text, suitable for further processing or display.'
• Refactor error messages to be actionable and error-category-aware. For configuration errors, return: 'Configuration error: TEXTRA_API_KEY not set. Ensure environment variables TEXTRA_API_KEY, TEXTRA_API_SECRET, TEXTRA_USER_NAME are configured on the server.' For network errors: 'Network timeout contacting Textra API. This is retryable, try again in 5 - 10 seconds.' For API errors: 'Textra API returned 429 (rate limited). Retry after 60 seconds.'
• Add tool annotations via fastMCP decorators or explicit schema fields to declare readOnlyHint=true (or equivalent idempotent/safe declaration).
• Add input validation with clear error feedback. Return structured errors: 'Invalid input: text must be 1 - 5000 characters. Got 0 characters (empty string). Provide non-empty Japanese text.'
• Consider adding optional parameters for translation options: target_language (currently hardcoded to 'en'; could support 'ja', 'zh', etc.), priority (standard, urgent), or quality_level (fast, standard, high). These would require upstream API support but would make the tool more versatile.

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

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