Fix MCP tools in PostHog Desktop

PostHog Desktop displays Self-driving reports about MCP Analytics. A scout analyzes tool calls, finds problems, and creates reports. Reports can include a pull request when you own the server.

Before you start

1. Install MCP Analytics – install the SDK in your MCP server so tool calls are captured.
2. Install PostHog Desktop – download the app and connect it to your project.

Whether you get a pull request depends on who owns the server

The scout can only propose a code fix for code you control, so the same finding takes one of two paths:

• You own the server. Your own MCP server, instrumented with the @posthog/mcp SDK. The report carries a fix loop metric – the number the fix is supposed to move – and auto-starts an implementation task. The coding agent works in a sandbox against your connected repo, pushes a branch, and opens a draft pull request.
• You don't own the server. You're analyzing PostHog's hosted MCP server, which is what most projects are doing. The report is filed for human review with no repository attached, and nothing opens a pull request. Read it as an upstream bug report and decide what to do with it.

Reports with unrelated fixes across several tools require human review, even when you own the server. Automatic fixes must address a specific schema, description, or handler problem.

What the scout watches

A scout reads $mcp_tool_call events for tools that need attention:

• High failure rates – a tool erroring far more than the rest
• Repeated calls – agents calling the same tool over and over to get what they need
• Slow or large responses – calls that take too long or return so much that they crowd the agent's context

It weighs each of these by volume and reach, so a tool failing for one developer in one session doesn't earn a report. What clears the bar gets grouped by the team that owns the tools and filed as a single report.

What you can do here

• Read the report – the failing tool, the pattern behind it, and the evidence from real calls.
• Ask questions – start a research task against the report to dig further before acting.
• Watch the agent work – when there's an implementation task, follow the live transcript and review the files it changed.
• Merge – the pull request opens on GitHub, and PostHog reflects the merged state back.

Nothing ships without you. The merge happens on GitHub, so a human is always the last step.

Start a fix yourself

Select Create fix task in the tool quality view to start a coding agent for a tool's failures. You do not need to wait for a scout report.

Connect the GitHub integration to enable the button. Select the repository where the agent works. The agent can only change code in the selected repository.

Related

• Explore tool quality in the web app.
• Learn how the loop works in the Self-driving docs.