Single tool server with a clearly named action verb ('perplexity_search'), good parameter schema with enums and descriptions, and functional security practices (URL sanitization, error handling). However, output schema is undocumented (returns plain string), descriptions are adequate but not optimized for LLM comprehension, and parameter descriptions lack format/constraint details. No composition, pagination, or result limiting patterns. Error handling is present but generic. Serviceable for a simple read-only integration, but falls short of production-grade baselines on output documentation and LLM-optimized descriptions.

• Document the output schema explicitly: 'Returns a string containing the Perplexity answer with inline markdown citation links formatted as [Title](URL). Citations are embedded in the text at relevant positions.'
• Expand tool description to include semantic guidance: 'Use for real-time information, news, research synthesis, or academic sources. Slower and more expensive than local search, call only when current information is essential. Supports web search, academic papers, or SEC filings via search_focus parameter.'
• For optional parameters, explain when an LLM should use them: 'search_focus="academic" when researching peer-reviewed papers; "sec" for financial/regulatory filings; "web" (default) for general current events and news.',
• Add validation error guidance: When validation fails (invalid search_focus or recency), include available options in the error: 'Invalid search_focus: got "news", must be one of: web, academic, sec. See tool description for when to use each.'
• Implement per-request error categorization: Return structured error objects {"error_type": "retryable|user_fixable|fatal", "message": "...", "guidance": "..."} instead of bare exceptions. Let LLM know whether to retry, ask the user, or fail the plan.
• Document citation structure and limits: Specify expected number of citations, max answer length, and truncation behavior. E.g., 'Typically returns 3-8 citations. Answers are capped at 4000 characters; longer results are truncated with ellipsis (...).'
• Add idempotency documentation: Clarify that repeated identical queries return identical results (searches are read-only and deterministic for the same query/timeframe).

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

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