Add rationale and is_suggestion to granular assignee tool

docs/feature-flags.md

@@ -75,7 +75,7 @@ runtime behavior (such as output formatting) won't appear here.
   - `type`: Type of this issue. Only use if issue types are enabled for this repository. Use list_issue_types tool to get valid type values for this repository or its owner organization. If the repository doesn't support issue types, omit this parameter. (string, optional)
 
 - **ui_get** - Get UI data
-  - **Required OAuth Scopes**: `repo`, `read:org`
+  - **Required OAuth Scopes (any of)**: `repo`, `read:org`
   - **Accepted OAuth Scopes**: `admin:org`, `read:org`, `repo`, `write:org`
   - `method`: The type of data to fetch (string, required)
   - `owner`: Repository owner (required for all methods) (string, required)
@@ -179,7 +179,7 @@ runtime behavior (such as output formatting) won't appear here.
 
 - **update_issue_assignees** - Update Issue Assignees
   - **Required OAuth Scopes**: `repo`
-  - `assignees`: GitHub usernames to assign to this issue (string[], required)
+  - `assignees`: GitHub usernames to assign to this issue. ([], required)
   - `issue_number`: The issue number to update (number, required)
   - `owner`: Repository owner (username or organization) (string, required)
   - `repo`: Repository name (string, required)

docs/insiders-features.md

@@ -69,7 +69,7 @@ The list below is generated from the Go source. It covers tool **inventory and s
   - `type`: Type of this issue. Only use if issue types are enabled for this repository. Use list_issue_types tool to get valid type values for this repository or its owner organization. If the repository doesn't support issue types, omit this parameter. (string, optional)
 
 - **ui_get** - Get UI data
-  - **Required OAuth Scopes**: `repo`, `read:org`
+  - **Required OAuth Scopes (any of)**: `repo`, `read:org`
   - **Accepted OAuth Scopes**: `admin:org`, `read:org`, `repo`, `write:org`
   - `method`: The type of data to fetch (string, required)
   - `owner`: Repository owner (required for all methods) (string, required)

pkg/github/__toolsnaps__/update_issue_assignees.snap

@@ -4,13 +4,48 @@
     "openWorldHint": true,
     "title": "Update Issue Assignees"
   },
-  "description": "Update the assignees of an existing issue. This replaces the current assignees with the provided list.",
+  "description": "Update the assignees of an existing issue. This replaces the current assignees with the provided list. When setting values, include a confidence level (LOW, MEDIUM, or HIGH) reflecting how certain you are about the choice.",
   "inputSchema": {
     "properties": {
       "assignees": {
-        "description": "GitHub usernames to assign to this issue",
+        "description": "GitHub usernames to assign to this issue.",
         "items": {
-          "type": "string"
+          "oneOf": [
+            {
+              "description": "GitHub username",
+              "type": "string"
+            },
+            {
+              "properties": {
+                "confidence": {
+                  "description": "How confident you are in this choice. Use 'HIGH' for clear signal or explicit user request, 'MEDIUM' for reasonable inference with some ambiguity, 'LOW' for best guess with limited signal.",
+                  "enum": [
+                    "LOW",
+                    "MEDIUM",
+                    "HIGH"
+                  ],
+                  "type": "string"
+                },
+                "is_suggestion": {
+                  "description": "If true, this assignee is sent to the API as a suggestion (suggest:true) rather than an applied assignment. Whether the assignee is applied or recorded as a proposal is determined by the API.",
+                  "type": "boolean"
+                },
+                "login": {
+                  "description": "GitHub username",
+                  "type": "string"
+                },
+                "rationale": {
+                  "description": "One concise sentence explaining what specifically about the issue led you to choose this assignee. State the concrete signal (e.g. 'Author of the component mentioned in the bug report').",
+                  "maxLength": 280,
+                  "type": "string"
+                }
+              },
+              "required": [
+                "login"
+              ],
+              "type": "object"
+            }
+          ]
         },
         "type": "array"
       },