---
title: "update_variable"
description: "Update a variable's name, description, and/or default_value."
sidebarTitle: "update_variable"
lastUpdated: "2026-09-23"
---

> **For AI agents:** the complete documentation index is at [llms.txt](/llms.txt). Append `.md` to any page URL for its markdown version.

{/* GENERATED FILE: do not edit by hand. Regenerate with: node scripts/generate.mjs */}

Update a variable's name, description, and/or default_value.

<Info>
  **Writes data · Idempotent · Calls external systems.**
</Info>

## Parameters

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `acknowledge` | boolean | No | Reset edit budget after user approval |
| `default_value` | string | No | New default value (string for single/secret, comma-separated for choice) |
| `description` | string | No | New description (optional, recommended) — overwrites the current value. A short sentence describing the variable's purpose helps future agents disambiguate it. |
| `name` | string | No | New name |
| `variable_id` | number | Yes | Variable id |

## Example arguments

Illustrative arguments an agent supplies when calling this tool:

```json
{
  "variable_id": 0
}
```

## Description

```text
Properties only — this tool does NOT touch per-variant values. To change one variant's value use set_variable_value; to copy values across variants use copy_variant_values. Variable type is immutable on the platform; this tool preserves it.

A description is optional but RECOMMENDED on update too — if the original variable was created without one, this is the place to add semantic context that future agents will rely on.
```

## Related

- [`set_variable_value`](/mcp/tools/variables/set_variable_value)
- [`copy_variant_values`](/mcp/tools/variables/copy_variant_values)

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