set_variable

Create/update a write-only account secret (uppercase name). Injected as env vars into container apps and as ${VAR} into proxy calls. Optionally pin which upstream hosts may receive it.

SERVERMcp SOURCEhttps://dataecho.ai/mcp

Medium RISK CLASS

Category Write

Parameters 32 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/ai-dataecho-mcp/set-variable.md

WHAT IT DOES

What set_variable does on Mcp

AI agents use set_variable to create or update resources in Mcp, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp environment.

Parameter	Type	Required	Description
`name`	string	Yes	UPPER_SNAKE_CASE variable name
`value`	string	Yes	Secret value (never readable back)
`allowedUpstreams`	array	—	Optional allow-list of upstream hosts

Parameters from the server's own tool schema.

RISK

Why set_variable is rated Medium

The tool creates or updates account secrets (environment variables), which is a Write operation — data is created or modified reversibly. The severity is medium rather than high because: (1) the secret is write-only, limiting read-back risks; (2) it's scoped to specific container apps and proxy calls; (3) secrets can be updated or deleted (reversible).

From the tool's definition Tool description: "Create/update a write-only account secret" — creates or modifies a secret variable that is injected into container apps and proxy calls. This is reversible modification of configuration/secrets data.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs set_variable safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Mcp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For set_variable, this is the rule to start with:

set_variable Rate-limited

set_variable 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_variable": {
      "limits": [
        {
          "counter": "set_variable_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Mcp, apply this rule, and every set_variable call is checked against it from then on.

FAQ

Questions about set_variable

What does the set_variable tool do? +

Create/update a write-only account secret (uppercase name). Injected as env vars into container apps and as ${VAR} into proxy calls. Optionally pin which upstream hosts may receive it. It is categorised as a Write tool in the Mcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does set_variable accept? +

set_variable accepts 3 parameters: name, value, allowedUpstreams. Required: name, value. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on set_variable? +

Register the MCP server in PolicyLayer and add a rule for set_variable: 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 Mcp. Nothing to install.

What risk level is set_variable? +

set_variable is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_variable? +

Yes. Add a rate_limit block to the set_variable 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.

How do I block set_variable completely? +

Set action: deny in the PolicyLayer policy for set_variable. 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.

What MCP server provides set_variable? +

set_variable is provided by the MCP server (https://dataecho.ai/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on , and thousands of servers like it.

This server

All 26 tools →

Across the catalogue

set-prioity on Kanban MCP Server →team_manager_set_sources on Team Manager MCP →qt_set_property on Qt → The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →