Improve description for #codingAgent tool reference to nudge the model to use the tool. (#7096)

Author: rebornix

package.json

@@ -3358,7 +3358,7 @@
 			{
 				"name": "github-pull-request_copilot-coding-agent",
 				"displayName": "%languageModelTools.github-pull-request_copilot-coding-agent.displayName%",
-				"modelDescription": "Completes the provided task using an asynchronous coding agent. Use when the user wants copilot continue completing a task in the background or asynchronously.",
+				"modelDescription": "Completes the provided task using an asynchronous coding agent. Use when the user wants copilot continue completing a task in the background or asynchronously. IMPORTANT: Use this tool LAST/FINAL when users mention '#github-pull-request_copilot-coding-agent' in their query. This indicates they want the task/job implemented by the remote coding agent after all other analysis, planning, and preparation is complete. Call this tool at the END to hand off the fully-scoped task to the asynchronous GitHub Copilot coding agent. The agent will create a new branch, implement the changes, and open a pull request. Always use this tool as the final step when the hashtag is mentioned, after completing any other necessary tools or analysis first.",
 				"when": "config.githubPullRequests.codingAgent.enabled",
 				"icon": "resources/icons/copilot.svg",
 				"canBeReferencedInPrompt": true,

package.nls.json

@@ -373,5 +373,5 @@
 	"languageModelTools.github-pull-request_activePullRequest.displayName": "Active Pull Request",
 	"languageModelTools.github-pull-request_activePullRequest.description": "Get information about the active GitHub pull request. This information includes: comments, files changed, pull request title + description, pull request state, and pull request status checks/CI.",
 	"languageModelTools.github-pull-request_copilot-coding-agent.displayName": "Copilot Coding Agent",
-	"languageModelTools.github-pull-request_copilot-coding-agent.userDescription": "Complete a task asynchronously using the current chat context and in-progress work."
+	"languageModelTools.github-pull-request_copilot-coding-agent.userDescription": "Completes the provided task using an asynchronous coding agent. Use when the user wants copilot continue completing a task in the background or asynchronously. Launch an autonomous GitHub Copilot agent to work on coding tasks in the background. The agent will create a new branch, implement the requested changes, and open a pull request with the completed work."
 }