Various tools are missing enumerated values

[williammartin]

Description

When running the conformance tests we saw that a lot of the tools schemas were using string types rather than enum types. I would think that the MCP Host would be able to make better use of the fields if it understood the values were constrained.

Specifically, we're looking at:

• list_issues: direction, sort and state
• update_issue: state
• search_code: order
• search_issues: order and sort
• search_users: order and sort

 Error: Received unexpected error:
 inputSchema mismatch for tool "list_issues":
 conformance_test.inputSchema{
 Type: "object",
 Properties: map[string]any{
 "direction": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("asc"), string("desc")},
 "type": string("string"),
 },
 ...
 "sort": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("created"), string("updated"), string("comments")},
 "type": string("string"),
 },
 "state": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("open"), string("closed"), string("all")},
 "type": string("string"),
 },
 },
 Required: {"owner", "repo"},
 }

 inputSchema mismatch for tool "update_issue":
 conformance_test.inputSchema{
 Type: "object",
 Properties: map[string]any{
 ...
 "state": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("open"), string("closed")},
 "type": string("string"),
 },
 "title": map[string]any{"type": string("string"), ...},
 },
 Required: {"owner", "repo", "issue_number"},
 }

 inputSchema mismatch for tool "search_code":
 conformance_test.inputSchema{
 Type: "object",
 Properties: map[string]any{
 "order": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("asc"), string("desc")},
 "type": string("string"),
 },
 ...
 }

 inputSchema mismatch for tool "search_issues":
 conformance_test.inputSchema{
 Type: "object",
 Properties: map[string]any{
 "order": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("asc"), string("desc")},
 "type": string("string"),
 },
 ...
 "sort": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{
 - string("comments"), string("reactions"), string("reactions-+1"),
 - string("reactions--1"), string("reactions-smile"),
 - string("reactions-thinking_face"), string("reactions-heart"),
 - string("reactions-tada"), string("interactions"), string("created"),
 - string("updated"),
 - },
 "type": string("string"),
 },
 },
 Required: {"q"},
 }

 inputSchema mismatch for tool "search_users":
 conformance_test.inputSchema{
 Type: "object",
 Properties: map[string]any{
 "order": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("asc"), string("desc")},
 "type": string("string"),
 },
 ...
 "sort": map[string]any{
 ... // 1 ignored entry
 - "enum": []any{string("followers"), string("repositories"), string("joined")},
 "type": string("string"),
 },
 },
 Required: {"q"},
 }

[williammartin]

I have a branch with this fix already.