Single tool 'fetch_url' has a clear action verb and reasonable description (127 chars, within 10-1024 range). Input schema is present with three parameters, all typed as string/integer. However, parameter descriptions are minimal (e.g., 'Caller identifier for rate limiting' lacks context on format/constraints). Output schema is not documented in the tool definition, the FetchResult dataclass exists in code but is not exposed as a formal schema in the MCP tool registration. Error handling is implemented server-side (SSRF validation, DNS checks, rate limiting) but error responses are not documented in the tool description, leaving LLMs unaware of recovery paths. No tool annotations (readOnlyHint, destructiveHint, idempotentHint) despite the tool being read-only.

• Add formal output schema to the MCP tool definition documenting all FetchResult fields (ok, fetch_status, blocked_reason, final_url, status_code, content_type, title, markdown, fetched_at, redirects, raw_bytes, decompressed_bytes, truncated, attempts, retried, retryable_error, last_error, security_blocked, render_mode, fallback_used, shell_only, js_required) with types and descriptions.
• Enhance parameter descriptions: 'max_tokens' → 'Maximum tokens to return in markdown content (default: 3000, range: 100-50000)'; 'caller_id' → 'Caller identifier for rate limiting (alphanumeric, max 64 chars; used to track per-caller request rate)'; 'url' → 'The URL to fetch (http or https only; must resolve to a public IP; max 2048 chars)'.
• Document error scenarios in tool description: 'Returns fetch_status indicating success or failure reason (e.g., invalid_scheme, dns_resolution_failed, ip_blocked, rate_limit_exceeded, timeout, content_too_large). On error, blocked_reason field explains why. Retryable errors set retryable_error=true.'
• Add tool annotations: set readOnlyHint=true and idempotentHint=true to signal that repeated calls with the same URL produce the same result and have no side effects.
• Standardize response field names to match parameter names where possible: rename 'content_markdown' → 'markdown' (already done), ensure 'final_url' is documented as the resolved URL after redirects, and add a 'url' echo field for clarity.

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

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