Update an existing memory in Memory Crystal. Use to correct errors, add new information, or update the status of a memory. Provide the memoryId and only the fields you want to change.
AI agents use crystal_edit to create or update resources in Memory Crystal MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Memory Crystal MCP Server environment.
This tool modifies existing data (memory records) in a reversible manner. Updates can be corrected or reverted. While it affects persistent state, it does not delete data irreversibly (Destructive), execute code (Execute), or involve financial operations (Financial).
From the tool's definition Tool description explicitly states 'Update an existing memory' and 'add new information, or update the status of a memory.' These are reversible modifications with no deletion or irreversible effects. The tool accepts a memoryId and selective field updates.
Documented attack patterns abuse exactly the kind of access crystal_edit gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Memory Crystal MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for crystal_edit:
{
"version": "1",
"default": "deny",
"tools": {
"crystal_edit": {
"limits": [
{
"counter": "crystal_edit_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}crystal_edit 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.
Free to start. No card required.
Update an existing memory in Memory Crystal. Use to correct errors, add new information, or update the status of a memory. Provide the memoryId and only the fields you want to change. It is categorised as a Write tool in the Memory Crystal MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Memory Crystal MCP Server MCP server in PolicyLayer and add a rule for crystal_edit: 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 Memory Crystal MCP Server. Nothing to install.
crystal_edit 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 crystal_edit 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 crystal_edit. 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.
crystal_edit is provided by the Memory Crystal MCP Server MCP server (memorycrystal/memorycrystal). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Memory Crystal MCP Server, 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.
31 Memory Crystal MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.