Modify existing table schema (add columns, rename tables, etc.)
AI agents use alter_table to create or update resources in DBeaver MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your DBeaver MCP Server environment.
Altering table schemas (adding/renaming columns) modifies data structure but is reversible through additional ALTER statements. This qualifies as Write rather than Destructive because schema modifications can be undone.
From the tool's definition Tool name 'alter_table' and description 'Modify existing table schema (add columns, rename tables, etc.)' indicates reversible structural changes to database objects.
Documented attack patterns abuse exactly the kind of access alter_table gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and DBeaver MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for alter_table:
{
"version": "1",
"default": "deny",
"tools": {
"alter_table": {
"limits": [
{
"counter": "alter_table_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}alter_table 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 existing table schema (add columns, rename tables, etc.). It is categorised as a Write tool in the DBeaver MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the DBeaver MCP Server MCP server in PolicyLayer and add a rule for alter_table: 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 DBeaver MCP Server. Nothing to install.
alter_table 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 alter_table 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 alter_table. 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.
alter_table is provided by the DBeaver MCP Server MCP server (srthkdev/omnisql-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 21 DBeaver MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
21 DBeaver MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.