meta-ads-mcp

list_custom_audiences

Query your ad account to retrieve a complete list of defined custom audiences. Access and review your specific marketing segments for targeted ad campaigns.

Instructions

List custom audiences in the ad account.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_custom_audiences"
  }
}

Input Schema

Name	Required	Description
`after`	No	Pagination cursor for next page
`limit`	No	Number of results (default 25)
`fields`	No	Comma-separated fields to return
`account_id`	No	Ad account ID to query (e.g. 'act_123' or '123'). Falls back to META_AD_ACCOUNT_ID env var if omitted.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.6.1Oct 21, 2026

addedInput schema / properties / account_id

Added value: +{
+  "description": "Ad account ID to query (e.g. 'act_123' or '123'). Falls back to META_AD_ACCOUNT_ID env var if omitted.",
+  "type": "string"
+}

First observedv1.2.0Mar 19, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full disclosure burden, yet it says nothing about pagination behavior, the default result limit, the read-only nature of the call, or the account_id environment-variable fallback. For a list tool with zero annotation coverage this leaves the agent under-informed about how calls behave.

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

Conciseness4/5

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

A single front-loaded sentence with no filler or repetition. It is appropriately tight, though its brevity borders on under-specification rather than true conciseness.

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

Completeness2/5

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

With no annotations, no output schema, and four parameters of which all are optional, the description does not tell the agent how results are paginated, what the default page size implies, or how account context is resolved. The schema covers the parameters, but behavioral completeness is thin.

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 description coverage is 100%, with after, limit, fields, and account_id all documented including the env-var fallback, so the schema does the heavy lifting. The description adds no syntax or format detail beyond that, so baseline 3 applies.

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?

The description names a specific verb ('List') and resource ('custom audiences') scoped to the ad account, so an agent can tell what it does. It does not distinguish itself from siblings like list_saved_audiences or get_audience, which leaves some ambiguity about which listing tool to pick.

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

Usage Guidelines2/5

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

There is no when-to-use guidance, no exclusions, and no mention of the alternative audience-listing or retrieval tools. The agent must infer context entirely from the tool name and the sibling list.

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

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