Revisit errors returned: Protocol Errors vs Tool Execution Errors

[jirispilka]

https://modelcontextprotocol.io/specification/2025-06-18/server/tools#error-handling

• Protocol errors indicate the request is malformed or invalid; the client should not retry with the same request.
• Tool execution errors indicate the request was valid but execution failed; the client may retry or handle the error based on the content.

Other issues:

Error #1 - search-actors with invalid limit:

When limit exceeds 100, tool fails with generic "Tool execution failed"
Recommendation: Return error like: "Invalid limit parameter: 150. Maximum allowed limit is 100."

Error #3 - search-apify-docs with empty query:

Empty query fails with generic "Tool execution failed"
Recommendation: Return error like: "Query parameter is required and cannot be empty."

Error #4 - apify-slash-rag-web-browser missing required param:

Missing required query parameter fails with generic "Tool execution failed"
Recommendation: Return validation error like: "Missing required parameter 'query'. Please provide a search term or URL."