Modify a column in an existing table.
AI agents use mysql_alter_table_modify_column to create or update resources in Mysql — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mysql environment.
Modifying a table column is a Write operation—it creates or modifies data structures reversibly. While serious and requiring careful handling, it is not Destructive (the original column data may be preserved depending on modification type) nor Irreversible by definition.
From the tool's definition Tool name contains 'alter_table_modify_column' and description states 'Modify a column in an existing table.' This is a schema modification operation that changes table structure.
Documented attack patterns abuse exactly the kind of access mysql_alter_table_modify_column gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mysql, and nothing reaches the server without passing your rules. This is the rule we recommend for mysql_alter_table_modify_column:
{
"version": "1",
"default": "deny",
"tools": {
"mysql_alter_table_modify_column": {
"limits": [
{
"counter": "mysql_alter_table_modify_column_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}mysql_alter_table_modify_column 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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Modify a column in an existing table. It is categorised as a Write tool in the Mysql MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mysql MCP server in PolicyLayer and add a rule for mysql_alter_table_modify_column: 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 Mysql. Nothing to install.
mysql_alter_table_modify_column 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 mysql_alter_table_modify_column 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 mysql_alter_table_modify_column. 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.
mysql_alter_table_modify_column is provided by the Mysql MCP server (mukul975/mysql-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mysql, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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233 Mysql tools catalogued and risk-classified — across an index of 43,000+ MCP servers.