PackageTrack MCP has three tools with clear, domain-specific purposes (package_changes, package_versions, project_report). All three have descriptions and input schemas with enums for ecosystem selection. However, critical gaps limit production readiness: (1) descriptions are functional but lack LLM-optimized guidance on WHEN to use each tool vs alternatives; (2) parameter descriptions are minimal (ecosystem, name, project lack context on expected formats or constraints); (3) no output schemas documented, LLMs cannot predict response structure for downstream planning; (4) error handling is absent from tool definitions, no guidance on retryability or recovery paths; (5) no tool annotations (readOnlyHint, idempotentHint) despite all three being read-only operations. The code shows thoughtful error messages in http_failure() and _unheld(), but these are not surfaced in tool contracts. Baseline: 194 chars avg description (these are ~100-150 chars), 72 chars avg param annotation (these are ~30-50 chars).

• Document output schemas for all three tools. Show example response structure with field names, types (string, array, object), and what each field means. Include pagination info if applicable.
• Expand parameter descriptions: 'ecosystem' → 'Package ecosystem (cargo, composer, go, maven, npm, nuget, pub, pypi). Determines which registry to query.'; 'max_chars' → 'Maximum characters per release note (default 3000, max 10000). Larger values return full changelogs.'
• Add tool annotations: set readOnlyHint=true and idempotentHint=true on all three tools so agents know they are safe to retry.
• Clarify project_report's API key requirement: 'Requires PACKAGETRACK_API_KEY environment variable set on the server. Contact packagetrack.dev to obtain a key.'
• Enhance tool descriptions with WHEN guidance: 'Call package_changes before upgrading to see what changed. Call package_versions first if you need to know available versions or check for withdrawn releases.'