Support issue comment reactions in add_issue_comment

Add optional comment_id support so the default add_issue_comment tool can react to a specific issue or pull request comment without exposing a separate default reaction tool. Keep body creation tied to issue_number and require reaction targets to provide either issue_number or comment_id.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SamMorrowDrums

README.md

@@ -842,7 +842,8 @@ The following sets of tools are available:
 - **add_issue_comment** - Add comment to issue or pull request
   - **Required OAuth Scopes**: `repo`
   - `body`: Comment content. Required unless reaction is provided. (string, optional)
-  - `issue_number`: Issue number to comment on or react to (number, required)
+  - `comment_id`: The numeric ID of the issue or pull request comment to react to. Use this for reactions to comments; omit it to react to the issue or pull request itself. (number, optional)
+  - `issue_number`: Issue or pull request number to comment on or react to. Required when body is provided, or when reaction targets an issue or pull request. (number, optional)
   - `owner`: Repository owner (string, required)
   - `reaction`: Emoji reaction to add. Required unless body is provided. (string, optional)
   - `repo`: Repository name (string, required)

pkg/github/__toolsnaps__/add_issue_comment.snap

@@ -2,15 +2,20 @@
   "annotations": {
     "title": "Add comment to issue or pull request"
   },
-  "description": "Add a comment and/or reaction to a specific issue in a GitHub repository. Use this tool with pull requests as well (in this case pass pull request number as issue_number), but only if user is not asking specifically to add or react to review comments. At least one of body or reaction is required.",
+  "description": "Add a comment and/or reaction to a specific issue or issue comment in a GitHub repository. Use this tool with pull requests as well (in this case pass pull request number as issue_number), but only if user is not asking specifically to add or react to review comments. At least one of body or reaction is required.",
   "inputSchema": {
     "properties": {
       "body": {
         "description": "Comment content. Required unless reaction is provided.",
         "type": "string"
       },
+      "comment_id": {
+        "description": "The numeric ID of the issue or pull request comment to react to. Use this for reactions to comments; omit it to react to the issue or pull request itself.",
+        "minimum": 1,
+        "type": "number"
+      },
       "issue_number": {
-        "description": "Issue number to comment on or react to",
+        "description": "Issue or pull request number to comment on or react to. Required when body is provided, or when reaction targets an issue or pull request.",
         "type": "number"
       },
       "owner": {
@@ -38,8 +43,7 @@
     },
     "required": [
       "owner",
-      "repo",
-      "issue_number"
+      "repo"
     ],
     "type": "object"
   },

pkg/github/issues.go

@@ -1057,7 +1057,7 @@ func AddIssueComment(t translations.TranslationHelperFunc) inventory.ServerTool
 		ToolsetMetadataIssues,
 		mcp.Tool{
 			Name:        "add_issue_comment",
-			Description: t("TOOL_ADD_ISSUE_COMMENT_DESCRIPTION", "Add a comment and/or reaction to a specific issue in a GitHub repository. Use this tool with pull requests as well (in this case pass pull request number as issue_number), but only if user is not asking specifically to add or react to review comments. At least one of body or reaction is required."),
+			Description: t("TOOL_ADD_ISSUE_COMMENT_DESCRIPTION", "Add a comment and/or reaction to a specific issue or issue comment in a GitHub repository. Use this tool with pull requests as well (in this case pass pull request number as issue_number), but only if user is not asking specifically to add or react to review comments. At least one of body or reaction is required."),
 			Annotations: &mcp.ToolAnnotations{
 				Title:        t("TOOL_ADD_ISSUE_COMMENT_USER_TITLE", "Add comment to issue or pull request"),
 				ReadOnlyHint: false,
@@ -1075,7 +1075,12 @@ func AddIssueComment(t translations.TranslationHelperFunc) inventory.ServerTool
 					},
 					"issue_number": {
 						Type:        "number",
-						Description: "Issue number to comment on or react to",
+						Description: "Issue or pull request number to comment on or react to. Required when body is provided, or when reaction targets an issue or pull request.",
+					},
+					"comment_id": {
+						Type:        "number",
+						Description: "The numeric ID of the issue or pull request comment to react to. Use this for reactions to comments; omit it to react to the issue or pull request itself.",
+						Minimum:     jsonschema.Ptr(1.0),
 					},
 					"body": {
 						Type:        "string",
@@ -1087,7 +1092,7 @@ func AddIssueComment(t translations.TranslationHelperFunc) inventory.ServerTool
 						Enum:        []any{"+1", "-1", "laugh", "confused", "heart", "hooray", "rocket", "eyes"},
 					},
 				},
-				Required: []string{"owner", "repo", "issue_number"},
+				Required: []string{"owner", "repo"},
 			},
 		},
 		[]scopes.Scope{scopes.Repo},
@@ -1100,9 +1105,23 @@ func AddIssueComment(t translations.TranslationHelperFunc) inventory.ServerTool
 			if err != nil {
 				return utils.NewToolResultError(err.Error()), nil, nil
 			}
-			issueNumber, err := RequiredInt(args, "issue_number")
-			if err != nil {
-				return utils.NewToolResultError(err.Error()), nil, nil
+			var issueNumber int
+			hasIssueNumber := false
+			if _, ok := args["issue_number"]; ok {
+				issueNumber, err = RequiredInt(args, "issue_number")
+				if err != nil {
+					return utils.NewToolResultError(err.Error()), nil, nil
+				}
+				hasIssueNumber = true
+			}
+			var commentID int64
+			hasCommentID := false
+			if _, ok := args["comment_id"]; ok {
+				commentID, err = RequiredBigInt(args, "comment_id")
+				if err != nil {
+					return utils.NewToolResultError(err.Error()), nil, nil
+				}
+				hasCommentID = true
 			}
 			body, hasBody, err := OptionalParamOK[string](args, "body")
 			if err != nil {
@@ -1115,6 +1134,12 @@ func AddIssueComment(t translations.TranslationHelperFunc) inventory.ServerTool
 			if !hasBody && !hasReaction {
 				return utils.NewToolResultError("at least one of body or reaction is required"), nil, nil
 			}
+			if hasBody && !hasIssueNumber {
+				return utils.NewToolResultError("issue_number is required when body is provided"), nil, nil
+			}
+			if hasReaction && !hasIssueNumber && !hasCommentID {
+				return utils.NewToolResultError("issue_number or comment_id is required when reaction is provided"), nil, nil
+			}
 			if hasBody && body == "" {
 				return utils.NewToolResultError("body cannot be empty when provided"), nil, nil
 			}
@@ -1154,15 +1179,28 @@ func AddIssueComment(t translations.TranslationHelperFunc) inventory.ServerTool
 
 			var reactionResponse *MinimalResponse
 			if hasReaction {
-				reaction, resp, err := client.Reactions.CreateIssueReaction(ctx, owner, repo, issueNumber, reactionContent)
-				if err != nil {
-					return ghErrors.NewGitHubAPIErrorResponse(ctx, "failed to add reaction to issue", resp, err), nil, nil
-				}
-				defer func() { _ = resp.Body.Close() }()
+				if hasCommentID {
+					reaction, resp, err := client.Reactions.CreateIssueCommentReaction(ctx, owner, repo, commentID, reactionContent)
+					if err != nil {
+						return ghErrors.NewGitHubAPIErrorResponse(ctx, "failed to add reaction to issue comment", resp, err), nil, nil
+					}
+					defer func() { _ = resp.Body.Close() }()
+
+					reactionResponse = &MinimalResponse{
+						ID:  fmt.Sprintf("%d", reaction.GetID()),
+						URL: fmt.Sprintf("%srepos/%s/%s/issues/comments/%d/reactions/%d", client.BaseURL(), owner, repo, commentID, reaction.GetID()),
+					}
+				} else {
+					reaction, resp, err := client.Reactions.CreateIssueReaction(ctx, owner, repo, issueNumber, reactionContent)
+					if err != nil {
+						return ghErrors.NewGitHubAPIErrorResponse(ctx, "failed to add reaction to issue", resp, err), nil, nil
+					}
+					defer func() { _ = resp.Body.Close() }()
 
-				reactionResponse = &MinimalResponse{
-					ID:  fmt.Sprintf("%d", reaction.GetID()),
-					URL: fmt.Sprintf("%srepos/%s/%s/issues/%d/reactions/%d", client.BaseURL(), owner, repo, issueNumber, reaction.GetID()),
+					reactionResponse = &MinimalResponse{
+						ID:  fmt.Sprintf("%d", reaction.GetID()),
+						URL: fmt.Sprintf("%srepos/%s/%s/issues/%d/reactions/%d", client.BaseURL(), owner, repo, issueNumber, reaction.GetID()),
+					}
 				}
 			}
 

pkg/github/issues_test.go

@@ -571,9 +571,10 @@ func Test_AddIssueComment(t *testing.T) {
 	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "owner")
 	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "repo")
 	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "issue_number")
+	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "comment_id")
 	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "body")
 	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "reaction")
-	assert.ElementsMatch(t, tool.InputSchema.(*jsonschema.Schema).Required, []string{"owner", "repo", "issue_number"})
+	assert.ElementsMatch(t, tool.InputSchema.(*jsonschema.Schema).Required, []string{"owner", "repo"})
 
 	// Setup mock comment for success case
 	mockComment := &github.IssueComment{
@@ -4185,9 +4186,10 @@ func TestAddIssueComment(t *testing.T) {
 	assert.Contains(t, schema.Properties, "owner")
 	assert.Contains(t, schema.Properties, "repo")
 	assert.Contains(t, schema.Properties, "issue_number")
+	assert.Contains(t, schema.Properties, "comment_id")
 	assert.Contains(t, schema.Properties, "body")
 	assert.Contains(t, schema.Properties, "reaction")
-	assert.ElementsMatch(t, schema.Required, []string{"owner", "repo", "issue_number"})
+	assert.ElementsMatch(t, schema.Required, []string{"owner", "repo"})
 
 	mockComment := &github.IssueComment{
 		ID:      github.Ptr(int64(456)),
@@ -4230,6 +4232,18 @@ func TestAddIssueComment(t *testing.T) {
 				"reaction":     "heart",
 			},
 		},
+		{
+			name: "successful reaction to issue comment",
+			mockedClient: MockHTTPClientWithHandlers(map[string]http.HandlerFunc{
+				PostReposIssuesCommentsReactionsByOwnerByRepoByCommentID: mockResponse(t, http.StatusCreated, mockReaction),
+			}),
+			requestArgs: map[string]any{
+				"owner":      "owner",
+				"repo":       "repo",
+				"comment_id": float64(999),
+				"reaction":   "heart",
+			},
+		},
 		{
 			name: "successful comment and reaction to issue",
 			mockedClient: MockHTTPClientWithHandlers(map[string]http.HandlerFunc{
@@ -4255,14 +4269,24 @@ func TestAddIssueComment(t *testing.T) {
 			expectedToolErrMsg: "at least one of body or reaction is required",
 		},
 		{
-			name: "missing required parameter issue_number",
+			name: "missing target for reaction",
 			requestArgs: map[string]any{
 				"owner":    "owner",
 				"repo":     "repo",
 				"reaction": "heart",
 			},
 			expectToolError:    true,
-			expectedToolErrMsg: "missing required parameter: issue_number",
+			expectedToolErrMsg: "issue_number or comment_id is required when reaction is provided",
+		},
+		{
+			name: "missing issue_number for body",
+			requestArgs: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+				"body":  "This is a comment",
+			},
+			expectToolError:    true,
+			expectedToolErrMsg: "issue_number is required when body is provided",
 		},
 	}