Save a note for your future self - findings, solutions, gotchas, etc. TIP: Write notes after completing tasks so you remember next time
AI agents use write_note to create or update resources in Claude Slack — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Claude Slack environment.
This tool creates new note records or modifies existing ones in a reversible manner. It has no side effects beyond storing data in the notes system. The blast radius is minimal—a misused note might contain incorrect information but cannot delete data, execute commands, or affect other systems. This is a straightforward Write operation with low severity impact.
From the tool's definition Tool name 'write_note' and description explicitly states 'Save a note' which is a create/modify operation. The description clarifies it stores findings and solutions for future reference.
Documented attack patterns abuse exactly the kind of access write_note gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Claude Slack, and nothing reaches the server without passing your rules. This is the rule we recommend for write_note:
{
"version": "1",
"default": "deny",
"tools": {
"write_note": {
"limits": [
{
"counter": "write_note_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}write_note stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Save a note for your future self - findings, solutions, gotchas, etc. TIP: Write notes after completing tasks so you remember next time. It is categorised as a Write tool in the Claude Slack MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Claude Slack MCP server in PolicyLayer and add a rule for write_note: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Claude Slack. Nothing to install.
write_note is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the write_note rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for write_note. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
write_note is provided by the Claude Slack MCP server (theo-nash/claude-slack). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Claude Slack, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
19 Claude Slack tools catalogued and risk-classified — across an index of 43,000+ MCP servers.