René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Document best Practice for Handling Argument Errors in MCP Tool Rendering","articleBody":"\nI'm uncertain about the recommended approach for handling errors in MCP, especially when it comes to missing or invalid arguments.\n\nSpecifically:\nShould we **throw an exception**, or should we **catch the error and return it as part of the `McpSchema.CallToolResult`** so the LLM can understand what went wrong and possibly correct the request in a future interaction?\n\n#### Example Scenario:\n\nI have a tool that expects two parameters: `first_name` and `last_name`. It returns a simple greeting message.\nIf the request includes only `first_name` and `last_name` is null, how should the error be handled?\n\nOption 1 — **Throw an exception**:\n\n```java\ncatch (Exception e) {\n    throw new McpError(e);\n}\n```\n\nOption 2 — **Catch and return the error message**:\n\n```java\ncatch (Exception e) {\n    contents.add(\n        new McpSchema.TextContent(\"Error: \" + e.getMessage())\n    );\n}\n```\n\nWhich approach aligns better with MCP's error-handling philosophy and the intended LLM experience?\n","author":{"url":"https://github.com/Eraoui909","@type":"Person","name":"Eraoui909"},"datePublished":"2025-06-30T09:04:52.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/356/java-sdk/issues/356"}