Optimize context usage for getting an issue using the issue_read tool (#2022)

* minimize context usage using minimal types for get issue comments

* preserver reactions field

* add back author association

Author: tommaso-moro

pkg/github/issues.go

@@ -376,12 +376,9 @@ func GetIssue(ctx context.Context, client *github.Client, deps ToolDependencies,
 		}
 	}
 
-	r, err := json.Marshal(issue)
-	if err != nil {
-		return nil, fmt.Errorf("failed to marshal issue: %w", err)
-	}
+	minimalIssue := convertToMinimalIssue(issue)
 
-	return utils.NewToolResultText(string(r)), nil
+	return MarshalledTextResult(minimalIssue), nil
 }
 
 func GetIssueComments(ctx context.Context, client *github.Client, deps ToolDependencies, owner string, repo string, issueNumber int, pagination PaginationParams) (*mcp.CallToolResult, error) {

pkg/github/issues_test.go

@@ -345,15 +345,15 @@ func Test_GetIssue(t *testing.T) {
 
 			textContent := getTextResult(t, result)
 
-			var returnedIssue github.Issue
+			var returnedIssue MinimalIssue
 			err = json.Unmarshal([]byte(textContent.Text), &returnedIssue)
 			require.NoError(t, err)
-			assert.Equal(t, *tc.expectedIssue.Number, *returnedIssue.Number)
-			assert.Equal(t, *tc.expectedIssue.Title, *returnedIssue.Title)
-			assert.Equal(t, *tc.expectedIssue.Body, *returnedIssue.Body)
-			assert.Equal(t, *tc.expectedIssue.State, *returnedIssue.State)
-			assert.Equal(t, *tc.expectedIssue.HTMLURL, *returnedIssue.HTMLURL)
-			assert.Equal(t, *tc.expectedIssue.User.Login, *returnedIssue.User.Login)
+			assert.Equal(t, tc.expectedIssue.GetNumber(), returnedIssue.Number)
+			assert.Equal(t, tc.expectedIssue.GetTitle(), returnedIssue.Title)
+			assert.Equal(t, tc.expectedIssue.GetBody(), returnedIssue.Body)
+			assert.Equal(t, tc.expectedIssue.GetState(), returnedIssue.State)
+			assert.Equal(t, tc.expectedIssue.GetHTMLURL(), returnedIssue.HTMLURL)
+			assert.Equal(t, tc.expectedIssue.GetUser().GetLogin(), returnedIssue.User.Login)
 		})
 	}
 }

pkg/github/minimal_types.go

@@ -136,6 +136,43 @@ type MinimalProject struct {
 	OwnerType        string            `json:"owner_type,omitempty"`
 }
 
+// MinimalReactions is the trimmed output type for reaction summaries, dropping the API URL.
+type MinimalReactions struct {
+	TotalCount int `json:"total_count"`
+	PlusOne    int `json:"+1"`
+	MinusOne   int `json:"-1"`
+	Laugh      int `json:"laugh"`
+	Confused   int `json:"confused"`
+	Heart      int `json:"heart"`
+	Hooray     int `json:"hooray"`
+	Rocket     int `json:"rocket"`
+	Eyes       int `json:"eyes"`
+}
+
+// MinimalIssue is the trimmed output type for issue objects to reduce verbosity.
+type MinimalIssue struct {
+	Number            int               `json:"number"`
+	Title             string            `json:"title"`
+	Body              string            `json:"body,omitempty"`
+	State             string            `json:"state"`
+	StateReason       string            `json:"state_reason,omitempty"`
+	Draft             bool              `json:"draft,omitempty"`
+	Locked            bool              `json:"locked,omitempty"`
+	HTMLURL           string            `json:"html_url"`
+	User              *MinimalUser      `json:"user,omitempty"`
+	AuthorAssociation string            `json:"author_association,omitempty"`
+	Labels            []string          `json:"labels,omitempty"`
+	Assignees         []string          `json:"assignees,omitempty"`
+	Milestone         string            `json:"milestone,omitempty"`
+	Comments          int               `json:"comments,omitempty"`
+	Reactions         *MinimalReactions `json:"reactions,omitempty"`
+	CreatedAt         string            `json:"created_at,omitempty"`
+	UpdatedAt         string            `json:"updated_at,omitempty"`
+	ClosedAt          string            `json:"closed_at,omitempty"`
+	ClosedBy          string            `json:"closed_by,omitempty"`
+	IssueType         string            `json:"issue_type,omitempty"`
+}
+
 // MinimalPullRequest is the trimmed output type for pull request objects to reduce verbosity.
 type MinimalPullRequest struct {
 	Number             int              `json:"number"`
@@ -180,6 +217,72 @@ type MinimalPRBranchRepo struct {
 
 // Helper functions
 
+func convertToMinimalIssue(issue *github.Issue) MinimalIssue {
+	m := MinimalIssue{
+		Number:            issue.GetNumber(),
+		Title:             issue.GetTitle(),
+		Body:              issue.GetBody(),
+		State:             issue.GetState(),
+		StateReason:       issue.GetStateReason(),
+		Draft:             issue.GetDraft(),
+		Locked:            issue.GetLocked(),
+		HTMLURL:           issue.GetHTMLURL(),
+		User:              convertToMinimalUser(issue.GetUser()),
+		AuthorAssociation: issue.GetAuthorAssociation(),
+		Comments:          issue.GetComments(),
+	}
+
+	if issue.CreatedAt != nil {
+		m.CreatedAt = issue.CreatedAt.Format(time.RFC3339)
+	}
+	if issue.UpdatedAt != nil {
+		m.UpdatedAt = issue.UpdatedAt.Format(time.RFC3339)
+	}
+	if issue.ClosedAt != nil {
+		m.ClosedAt = issue.ClosedAt.Format(time.RFC3339)
+	}
+
+	for _, label := range issue.Labels {
+		if label != nil {
+			m.Labels = append(m.Labels, label.GetName())
+		}
+	}
+
+	for _, assignee := range issue.Assignees {
+		if assignee != nil {
+			m.Assignees = append(m.Assignees, assignee.GetLogin())
+		}
+	}
+
+	if closedBy := issue.GetClosedBy(); closedBy != nil {
+		m.ClosedBy = closedBy.GetLogin()
+	}
+
+	if milestone := issue.GetMilestone(); milestone != nil {
+		m.Milestone = milestone.GetTitle()
+	}
+
+	if issueType := issue.GetType(); issueType != nil {
+		m.IssueType = issueType.GetName()
+	}
+
+	if r := issue.Reactions; r != nil {
+		m.Reactions = &MinimalReactions{
+			TotalCount: r.GetTotalCount(),
+			PlusOne:    r.GetPlusOne(),
+			MinusOne:   r.GetMinusOne(),
+			Laugh:      r.GetLaugh(),
+			Confused:   r.GetConfused(),
+			Heart:      r.GetHeart(),
+			Hooray:     r.GetHooray(),
+			Rocket:     r.GetRocket(),
+			Eyes:       r.GetEyes(),
+		}
+	}
+
+	return m
+}
+
 func convertToMinimalPullRequest(pr *github.PullRequest) MinimalPullRequest {
 	m := MinimalPullRequest{
 		Number:         pr.GetNumber(),