internal/labels: add extra description

The description in the issue tracker might not be enough information.
Allow extra descriptive text about a category to be fed to the LLM.

Here I've included information about proposal scope from
https://go.dev/s/proposal. Although it didn't really help
with evaluation, I still think this feature is useful.

(Nothing I wrote, including phrases like "not gopls", could dissuade
the LLM from classifying go.dev/issue/69058, requesting a new gopls
feature, as a tool proposal.)

For #64.

Change-Id: I11563e065097e1176bd144f12c96c7f0285beaf2
Reviewed-on: https://go-review.googlesource.com/c/oscar/+/636716
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Tatiana Bradley <[email protected]>

internal/labels/labels.go

@@ -27,7 +27,8 @@ import (
 type Category struct {
 	Name        string // internal unique name
 	Label       string // issue tracker label
-	Description string
+	Description string // should match issue tracker
+	Extra       string // additional description, not in issue tracker
 }
 
 // IssueCategory returns the category chosen by the LLM for the issue, along with an explanation
@@ -57,7 +58,7 @@ func IssueCategoryFromList(ctx context.Context, cgen llm.ContentGenerator, iss *
 	var systemPrompt bytes.Buffer
 	systemPrompt.WriteString(categoryPrompt)
 	for _, cat := range cats {
-		fmt.Fprintf(&systemPrompt, "%s: %s\n", cat.Name, cat.Description)
+		fmt.Fprintf(&systemPrompt, "%s: %s\n%s\n\n", cat.Name, cat.Description, cat.Extra)
 	}
 
 	// Ask about the category of the issue.

internal/labels/static/categories.yaml

@@ -1,56 +1,99 @@
-# File of categories used to classify GitHub issues.
-# The category name is distinct from the name of the label used on the issue tracker.
-# The description of a label should match the description on the issue tracker.
+# Categories used to classify GitHub issues.
+# Each category has the following fields:
+#  name: the internal name of the category
+#  label: the name of the label on the issue tracker
+#  description: the label description on the issue tracker
+#  extra: additional information about the label, fed to the LLM along
+#         with the description
 categories:
   - name: bug
     label: BUGLABEL
     description: "Issues describing a bug in the Go implementation."
+
   - name: languageProposal
     label: LANGPROPLABEL
     description: Issues describing a requested change to the Go language specification.
+    extra: |
+      This should be used for any notable change or addition to the language.
+      “Notable” includes (but is not limited to): Any visible behavior changes
+      that need a GODEBUG setting for compatibility. Any other visible behavior
+      changes in existing functionality.
+
   - name: libraryProposal
     label: LIBPROPLABEL
     description: Issues describing a requested change to the Go standard library or x/ libraries, but not to a tool
+    extra: |
+      This should be used for any notable change or addition to the libraries.
+      “Notable” includes (but is not limited to): API changes in the main
+      repo and all golang.org/x repos. Any visible behavior changes that
+      need a GODEBUG setting for compatibility. Any other visible behavior
+      changes in existing functionality. Adoption or use of new protocols,
+      protocol versions, cryptographic algorithms, and the like, even in an
+      implementation. Such changes are externally visible and require discussion
+      and probably a GODEBUG setting.
+
   - name: toolProposal
     label: TOOLPROPLABEL
     description: Issues describing a requested change to a Go tool or command-line program.
+    extra: |
+      This should be used for any notable change or addition to the tools.
+      “Notable” includes (but is not limited to): Command-line changes to the
+      go command. Any visible behavior changes that need a GODEBUG setting
+      for compatibility. Any other visible behavior changes in existing
+      functionality. Adoption or use of new protocols, protocol versions,
+      cryptographic algorithms, and the like, even in an implementation. Such
+      changes are externally visible and require discussion and probably a
+      GODEBUG setting.
+      This does NOT includ changes to tools in x repos, like gopls, or third-party tools.
+
   - name: implementation
     label: IMPLABEL
     description: Issues describing a semantics-preserving change to the Go implementation.
+
   - name: accessRequest
     label: accessRequestLABEL
     description: Issues requesting builder or gomote access.
+
   - name: pkgsiteRemovalRequest
     label: pkgsite/package-removal
     description: Issues for package removal. See https://pkg.go.dev/about#removing-a-package
     # We don't label issues posted by gopherbot, so this label is probably unnecessary.
+
   - name: automation
     label: automationLABEL
     description: Issues created by gopherbot or watchflakes automation.
+
   - name: backport
     label: backportLABEL
     description: Issues created for requesting a backport of a change to a previous Go version.
+
   - name: builders
     label: Builders
     description: x/build issues (builders, bots, dashboards)
+
   - name: question
     label: questionLABEL
     description: Issues that are questions about using Go.
     # It may be too challenging for the LLM to decide is something is WAI. Consider removing this.
+
   - name: workingAsIntended
     label: WorkingAsIntended
     description: Issues describing something that is working as it is supposed to.
+
   - name: featureRequest
     label: FeatureRequestLABEL
     description: Issues asking for a new feature that does not need a proposal.
+
   - name: documentation
     label: Documentation
     description: Issues describing a change to documentation.
     # The LLM never seems to pick invalid.
+
   - name: invalid
     label: invalidLABEL
     description: Issues that are empty, incomplete, or spam.
     # The LLM never seems to pick other.
+
   - name: other
     label: otherLABEL
     description: None of the above.