René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"get_discussion and get_discussion_comments accept calls with missing required parameters instead of returning a validation error","articleBody":"### Describe the bug\n\nWhen `get_discussion` or `get_discussion_comments` is called without one of the required parameters (`owner`, `repo`, or `discussionNumber`), the tool does not return a parameter-validation error. Instead it silently substitutes a zero value and issues a GraphQL request, which returns a confusing API-level error rather than a clear message identifying the missing field.\n\n**Affected version:** current (tested against `ghcr.io/github/github-mcp-server` latest as of 2026-06)\n\n### Steps to reproduce\n\n1. Configure the MCP server normally.\n2. Call `get_discussion` with only `{\"repo\": \"myrepo\", \"discussionNumber\": 1}` (omitting `owner`).\n3. Observe that the tool returns a GraphQL error like `\"Could not resolve to a Repository\"` rather than a message indicating `owner` is required.\n\nRepeat with `get_discussion_comments` and any missing required field.\n\n### Expected behavior\n\nThe tool should return a structured error immediately: `\"missing required parameter: owner\"` (or equivalent), consistent with how `add_discussion_comment` and the other discussion write tools behave when a required parameter is absent.\n\n### Actual behavior\n\nThe tool issues a GraphQL query with the missing field set to its zero value (`\"\"` for strings, `0` for numbers) and returns whichever API error results from that invalid query.\n\n### Additional context\n\nThe write handlers in the same file (`add_discussion_comment`, `reply_to_discussion_comment`, etc.) were updated in PR #2718 to use explicit parameter validation that returns named errors on missing input. The two read handlers were not included in that pass and still use the legacy decoding pattern.\n","author":{"url":"https://github.com/rodboev","@type":"Person","name":"rodboev"},"datePublished":"2026-06-21T01:59:53.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/2740/github-mcp-server/issues/2740"}