ServiceNow MCP Server

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Get Table Schema

get_table_schema

Read-onlyIdempotent

Retrieve field definitions and data dictionary for a ServiceNow table, including inherited fields from parent tables, to understand schema structure.

Instructions

Get the data dictionary (field definitions) for a ServiceNow table, including inherited fields

Input Schema

Name	Required	Description
`limit`	No	Maximum number of fields to return (own fields first, then inherited)
`table_name`	Yes	The table name to get schema for
`include_inherited`	No	Include fields inherited from parent tables (e.g. cmdb_ci fields on cmdb_ci_server)

Output Schema

Name	Required	Description	Default
`note`	No
`table`	Yes
`fields`	Yes
`hierarchy`	Yes
`truncated`	No
`field_count`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.9.2Oct 23, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "field_count": {
+      "type": "integer"
+    },
+    "fields": {
+      "items": {
+        "additionalProperties": true,
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "hierarchy": {
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "note": {
+      "type": "string"
+    },
+    "table": {
+      "type": "string"
+    },
+    "truncated": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "table",
+    "hierarchy",
+    "field_count",
+    "fields"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv0.9.1Oct 14, 2026

changedInput schema / properties / include_inherited / description

Previous value: -"Include fields inherited from parent tables (e.g. task fields on incident)"New value: +"Include fields inherited from parent tables (e.g. cmdb_ci fields on cmdb_ci_server)"

Changed5 schema fields changedv0.7.0Sep 9, 2026

addedInput schema / properties / include_inherited

Added value: +{
+  "default": true,
+  "description": "Include fields inherited from parent tables (e.g. task fields on incident)",
+  "type": "boolean"
+}

changedInput schema / properties / limit / default
```
Previous value: -50New value: +200
```

changedInput schema / properties / limit / description

Previous value: -"Maximum number of fields to return"New value: +"Maximum number of fields to return (own fields first, then inherited)"

changedInput schema / properties / limit / maximum
```
Previous value: -500New value: +1000
```

changedOutput schema / (root)

Previous value: -{
-  "additionalProperties": true,
-  "type": "object"
-}New value: +null

First observedv0.5.1Aug 1, 2026

TDQS

A3.6/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is fully covered. The description adds the useful behavioral fact that inherited fields are included by default, but says nothing about ordering, truncation at the limit, or performance on large tables.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no filler; the key concept (data dictionary / field definitions) appears immediately with the table scope attached.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read-only schema lookup with full parameter documentation, annotations, and an output schema, the description covers what is needed. The only shortfall is absent guidance on cost/size (limit defaults to 200) for very wide tables.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so all three parameters (including the limit ordering note and the include_inherited example) are already documented in the schema. The description's mention of inherited fields merely echoes the schema, adding no new syntax or format detail.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Get the data dictionary (field definitions) for a ServiceNow table') and adds a scope qualifier about inherited fields. It is clearly distinguishable from record-level siblings like get_record or get_ci, though it never names an alternative explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied: an agent can infer this is a schema-discovery step before querying or building records. There is no explicit when-to-use/when-not guidance, no mention of alternatives like get_record, and no prerequisite context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.