Database tables, fields, relations, and constraints in the loaded schema. Changes apply immediately; use schema_undo to revert the last change. Ops: - op=ADD_CONSTRAINTS → ADD_CONSTRAINTS (req: constraints) - op=ADD_FIELDS_RELATIONS → ADD_FIELDS_AND_RELATIONS (req: fields, relations, tableDisplay...
AI agents use schema_table to create or update resources in Zion — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Zion environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
op | string | Yes | |
items | array | — | |
fields | array | — | |
appExId | string | null | — | |
relations | array | — | |
constraints | array | — | |
projectExId | string | — | |
showApiName | boolean | — | |
appVersionExId | string | null | — | |
tableDisplayName | string | — | |
columnDisplayName | string | — | |
customEmbeddingId | string | — |
Parameters from the server's own tool schema.
This tool modifies a live database schema immediately upon execution. While some ops are additive (Write), the DELETE_CONSTRAINTS and DELETE_FIELDS_RELATIONS operations can remove schema elements. However, since a schema_undo mechanism exists to revert the last change, these are not fully irreversible — placing the tool closer to Write than Destructive.
From the tool's definition Changes apply immediately; use schema_undo to revert the last change. Ops include ADD_CONSTRAINTS, ADD_FIELDS_RELATIONS, ADD_TABLES, ADD_EXTENSION, DELETE_CONSTRAINTS, DELETE_FIELDS_RELATIONS
Risk signalsHigh parameter count (16 properties)
Attacks that exploit this kind of access
Database tables, fields, relations, and constraints in the loaded schema. Changes apply immediately; use schema_undo to revert the last change. Ops: - op=ADD_CONSTRAINTS → ADD_CONSTRAINTS (req: constraints) - op=ADD_FIELDS_RELATIONS → ADD_FIELDS_AND_RELATIONS (req: fields, relations, tableDisplayName) - op=ADD_TABLES → ADD_TABLES (req: items) - op=ADD_EXTENSION → ADD_TABLE_EXTENSION (req: columnDisplayName, tableDisplayName) - op=DELETE_CONSTRAINTS → DELETE_CONSTRAINTS (req: constraints) - op=DELETE_FIELDS_RELATIONS → DELETE_FIELDS_AND_RELATIONS (req: fieldDisplayNames, relationFieldDisplayNamesInSourceTable, tableDisplayName) - op=DELETE_TABLES → DELETE_TABLES (req: tableDisplayNames) - op=DELETE_EXTENSION → DELETE_TABLE_EXTENSION (req: columnDisplayName, tableDisplayName) - op=LIST_NAMES → GET_ALL_TABLE_DISPLAY_NAMES - op=LIST_EMBEDDING_MODELS → GET_AVAILABLE_EMBEDDING_MODELS - op=GET_INFOS → GET_TABLE_INFOS (req: tableDisplayNames). It is categorised as a Write tool in the Zion MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
schema_table accepts 12 parameters: op, items, fields, appExId, relations, constraints, projectExId, showApiName, appVersionExId, tableDisplayName, columnDisplayName, customEmbeddingId. Required: op. The full parameter table on this page comes from the server's own tool schema.
Register the Zion MCP server in PolicyLayer and add a rule for schema_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 Zion. Nothing to install.
schema_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 schema_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 schema_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.
schema_table is provided by the Zion MCP server (zion-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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