Retrieve paginated publisher block lists for an ad account to manage ad placement exclusions.
List publisher block lists for the ad account. Returns paginated results.
| Name | Required | Description | Default |
|---|---|---|---|
| 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. |
Changes observed during successful MCP inspections.
v1.6.1Input schema / properties / account_idAdded 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"
+}v1.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It clearly implies a read-only listing operation and adds that results are paginated, but it does not disclose permissions, rate limits, or other operational behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short sentences, front-loaded with the core action and resource, with no unnecessary wording. The pagination note is useful and brief.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple optional-parameter list tool with full schema descriptions, the definition is mostly complete: it identifies the resource, scope, and pagination behavior. It could be slightly richer about the returned block-list objects, but no output schema is present and the key calling information is available.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the schema already explains account_id, after, limit, and fields. The description only reinforces the ad-account scope and pagination, adding little parameter-level meaning beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a clear verb and resource: 'List publisher block lists for the ad account.' This is specific enough to distinguish retrieval from the sibling mutation tools like create_block_list, add_to_block_list, and delete_block_list, though it does not explicitly name alternatives.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It states what the tool retrieves but gives no explicit guidance on when to use it versus related block-list tools or how it should be chosen over alternatives. The ad-account scope is implied but not framed as a selection condition.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.