set_card_custom_field

Set (or clear) a Custom Field value on a Trello card. The value input depends on the field type: for list/dropdown fields pass

SERVERTrello SOURCE@asapo/trello-mcp-server

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade D, identity unverified Pull the record →

This record as markdown: /tools/asapo-trello-mcp-server/set-card-custom-field.md

WHAT IT DOES

What set_card_custom_field does on Trello

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

RISK

Why set_card_custom_field is rated Medium

An AI agent can call set_card_custom_field faster than any human can review: one bad instruction and it creates or modifies resources in Trello by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs set_card_custom_field safely

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

set_card_custom_field Rate-limited

set_card_custom_field 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_card_custom_field": {
      "limits": [
        {
          "counter": "set_card_custom_field_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 Trello, apply this rule, and every set_card_custom_field call is checked against it from then on.

FAQ

Questions about set_card_custom_field

What does the set_card_custom_field tool do? +

Set (or clear) a Custom Field value on a Trello card. The value input depends on the field type: for list/dropdown fields pass. It is categorised as a Write tool in the Trello MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_card_custom_field? +

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

What risk level is set_card_custom_field? +

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

Can I rate-limit set_card_custom_field? +

Yes. Add a rate_limit block to the set_card_custom_field 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_card_custom_field completely? +

Set action: deny in the PolicyLayer policy for set_card_custom_field. 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_card_custom_field? +

set_card_custom_field is provided by the Trello MCP server (@asapo/trello-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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