diff --git a/README.md b/README.md
index 8ab95c8dc..29795dc8f 100644
--- a/README.md
+++ b/README.md
@@ -758,7 +758,7 @@ The following sets of tools are available:
   - `repo`: Repository name (string, required)
 
 - **assign_copilot_to_issue** - Assign Copilot to issue
-  - `issueNumber`: Issue number (number, required)
+  - `issue_number`: Issue number (number, required)
   - `owner`: Repository owner (string, required)
   - `repo`: Repository name (string, required)
 
diff --git a/pkg/github/__toolsnaps__/assign_copilot_to_issue.snap b/pkg/github/__toolsnaps__/assign_copilot_to_issue.snap
index 22c380055..354600147 100644
--- a/pkg/github/__toolsnaps__/assign_copilot_to_issue.snap
+++ b/pkg/github/__toolsnaps__/assign_copilot_to_issue.snap
@@ -6,13 +6,8 @@
   "description": "Assign Copilot to a specific issue in a GitHub repository.\n\nThis tool can help with the following outcomes:\n- a Pull Request created with source code changes to resolve the issue\n\n\nMore information can be found at:\n- https://docs.github.com/en/copilot/using-github-copilot/using-copilot-coding-agent-to-work-on-tasks/about-assigning-tasks-to-copilot\n",
   "inputSchema": {
     "type": "object",
-    "required": [
-      "owner",
-      "repo",
-      "issueNumber"
-    ],
     "properties": {
-      "issueNumber": {
+      "issue_number": {
         "type": "number",
         "description": "Issue number"
       },
@@ -24,7 +19,12 @@
         "type": "string",
         "description": "Repository name"
       }
-    }
+    },
+    "required": [
+      "owner",
+      "repo",
+      "issue_number"
+    ]
   },
   "name": "assign_copilot_to_issue",
   "icons": [
diff --git a/pkg/github/issues.go b/pkg/github/issues.go
index f06dc2d9d..626e2c2e9 100644
--- a/pkg/github/issues.go
+++ b/pkg/github/issues.go
@@ -1626,19 +1626,19 @@ func AssignCopilotToIssue(t translations.TranslationHelperFunc) inventory.Server
 						Type:        "string",
 						Description: "Repository name",
 					},
-					"issueNumber": {
+					"issue_number": {
 						Type:        "number",
 						Description: "Issue number",
 					},
 				},
-				Required: []string{"owner", "repo", "issueNumber"},
+				Required: []string{"owner", "repo", "issue_number"},
 			},
 		},
 		func(ctx context.Context, deps ToolDependencies, _ *mcp.CallToolRequest, args map[string]any) (*mcp.CallToolResult, any, error) {
 			var params struct {
-				Owner       string
-				Repo        string
-				IssueNumber int32
+				Owner       string `mapstructure:"owner"`
+				Repo        string `mapstructure:"repo"`
+				IssueNumber int32  `mapstructure:"issue_number"`
 			}
 			if err := mapstructure.Decode(args, &params); err != nil {
 				return utils.NewToolResultError(err.Error()), nil, nil
diff --git a/pkg/github/issues_test.go b/pkg/github/issues_test.go
index b810cede3..694b991dc 100644
--- a/pkg/github/issues_test.go
+++ b/pkg/github/issues_test.go
@@ -2175,8 +2175,8 @@ func TestAssignCopilotToIssue(t *testing.T) {
 	assert.NotEmpty(t, tool.Description)
 	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, "issueNumber")
-	assert.ElementsMatch(t, tool.InputSchema.(*jsonschema.Schema).Required, []string{"owner", "repo", "issueNumber"})
+	assert.Contains(t, tool.InputSchema.(*jsonschema.Schema).Properties, "issue_number")
+	assert.ElementsMatch(t, tool.InputSchema.(*jsonschema.Schema).Required, []string{"owner", "repo", "issue_number"})
 
 	var pageOfFakeBots = func(n int) []struct{} {
 		// We don't _really_ need real bots here, just objects that count as entries for the page
@@ -2197,9 +2197,9 @@ func TestAssignCopilotToIssue(t *testing.T) {
 		{
 			name: "successful assignment when there are no existing assignees",
 			requestArgs: map[string]any{
-				"owner":       "owner",
-				"repo":        "repo",
-				"issueNumber": float64(123),
+				"owner":        "owner",
+				"repo":         "repo",
+				"issue_number": float64(123),
 			},
 			mockedClient: githubv4mock.NewMockedHTTPClient(
 				githubv4mock.NewQueryMatcher(
@@ -2286,9 +2286,9 @@ func TestAssignCopilotToIssue(t *testing.T) {
 		{
 			name: "successful assignment when there are existing assignees",
 			requestArgs: map[string]any{
-				"owner":       "owner",
-				"repo":        "repo",
-				"issueNumber": float64(123),
+				"owner":        "owner",
+				"repo":         "repo",
+				"issue_number": float64(123),
 			},
 			mockedClient: githubv4mock.NewMockedHTTPClient(
 				githubv4mock.NewQueryMatcher(
@@ -2386,9 +2386,9 @@ func TestAssignCopilotToIssue(t *testing.T) {
 		{
 			name: "copilot bot not on first page of suggested actors",
 			requestArgs: map[string]any{
-				"owner":       "owner",
-				"repo":        "repo",
-				"issueNumber": float64(123),
+				"owner":        "owner",
+				"repo":         "repo",
+				"issue_number": float64(123),
 			},
 			mockedClient: githubv4mock.NewMockedHTTPClient(
 				// First page of suggested actors
@@ -2512,9 +2512,9 @@ func TestAssignCopilotToIssue(t *testing.T) {
 		{
 			name: "copilot not a suggested actor",
 			requestArgs: map[string]any{
-				"owner":       "owner",
-				"repo":        "repo",
-				"issueNumber": float64(123),
+				"owner":        "owner",
+				"repo":         "repo",
+				"issue_number": float64(123),
 			},
 			mockedClient: githubv4mock.NewMockedHTTPClient(
 				githubv4mock.NewQueryMatcher(