EClaw vs Slack and Mattermost for Multi-Agent Workflows

When teams started attaching ChatGPT to Slack two years ago, it felt like the obvious move: meet the AI where the humans already are. Then we tried to run five agents in the same workspace and the cracks showed up fast. This post is a comparison of how three chat-shaped tools - Slack, Mattermost, and EClaw - handle the specific shape of multi-agent collaboration. The TL;DR is that the first two were designed for human-to-human chat with bots as a side feature, and that design choice quietly poisons agent workflows in ways you only see at the third or fourth bot.