PostHog MCP Tool Names Too Long

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

I reported this to Posthog as well, but when adding the PostHog MCP to Cursor , Cursor errors saying some tool names are longer than 60 characters.

Not sure if this is a Posthog issue or a cursor issue so sharing with both companies.

I can’t attach a screenshot but in the Cursor MCP settings it says taht Some tools have naming issues and may be filtered out.

Posthog has a tool name over 60 characters.

Steps to Reproduce

Just add Posthog mcp and authenticate: Model Context Protocol (MCP) - Docs - PostHog

Expected Behavior

Cursor suppors longer than 60 char names unless this is a violation of MCP protocol.

Screenshots / Screen Recordings

cursor_bug.png
cursor_bug.png1706×1286 183 KB

Operating System

MacOS

Version Information

Version: 2.6.19
VSCode Version: 1.105.1
Commit: 224838f96445be37e3db643a163a817c15b36060
Date: 2026-03-12T04:07:27.435Z
Build Type: Stable
Release Track: Default
Electron: 39.4.0
Chromium: 142.0.7444.265
Node.js: 22.22.0
V8: 14.2.231.22-electron.0
OS: Darwin arm64 24.4.0

Does this stop you from using Cursor

No - Cursor works, but with this issue

6

Hey there!

The tool should actually work fine despite the warning. Our agent layer handles long names gracefully by truncating with a hash suffix, so everything from PostHog will function as expected. Try it out in an agent chat just to be sure.

That said, you’re right that the warning is wrong. The combined server + tool name is exactly 60 characters, and our check fires at “exceeds 60”, which 60 clearly doesn’t. Will report that as a bug!

On the 60-character limit itself, you’re also right that the MCP spec allows up to 128 characters. We use a more conservative internal limit (as do some other implementations), but we’ll follow up to see whether it needs to be raised.