ocireg-mcp demonstrates solid definition quality with clear naming conventions, complete parameter descriptions, and proper schema registration via the mcp-go framework. All 6 tools follow verb_noun naming patterns (get_*, list_). Descriptions are comprehensive and contextual. Tool annotations (readOnlyHint, destructiveHint, idempotentHint) are properly applied. However, output schemas for 2 of 6 tools are not fully visible in the source, and error handling guidance is minimal. Per-tool scores average 72, driven by strong naming/descriptions but incomplete schema visibility.

• Explicitly register output schemas for get_image_manifest and get_image_config via mcp.WithOutputSchema[ManifestResult]() or similar, mirroring the pattern used for get_image_info and list_tags. This ensures LLMs know what fields to expect in responses.
• Add recovery guidance to each tool description. Example for get_image_info: 'If image not found, verify the repository exists via list_tags(repository) and confirm the tag is spelled correctly.'
• Document the complete range for list_tags limit parameter: 'Limit (default: 100, min: 1, max: 1000).' This prevents LLMs from passing nonsensical values.
• Clarify decode_payload behavior when payload is not a DSSE envelope. Specify whether it returns the raw blob unchanged or raises an error.
• Add per-tool error examples in docs or inline comments (e.g., 'Error: digest not found in referrers list' -> 'Call list_referrers first to verify the artifact exists').