reddit_ads_list_carriersFetch mobile carriers available for Reddit Ads targeting. Use page tokens and max pages to collect and merge carrier lists.
List mobile carriers for targeting.
| Name | Required | Description | Default |
|---|---|---|---|
| max_pages | No | Follow pagination.next_url up to this many pages and merge results (default 1) | |
| page_size | No | Items per page (usually max 1000) | |
| page_token | No | Page token from a previous pagination.next_url |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is clear. The description adds no behavioral context beyond that, such as pagination behavior, authentication needs, or rate limits, and only restates the tool's purpose.
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?
A single, front-loaded sentence with zero wasted words. It is as concise as possible while still stating the tool's core purpose.
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 read-only reference-list tool, the description states what the tool does, and the schema covers pagination while annotations cover the safety profile. However, it lacks any usage guidance or return-shape context, leaving clear gaps beyond the minimum.
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% for all three optional pagination parameters, so the schema fully documents their meaning. The description adds no parameter-level detail, which is acceptable given the high schema coverage, yielding the baseline score of 3.
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?
States a specific verb ('List') and resource ('mobile carriers') with a clear targeting context. It does not explicitly differentiate from similar reference-list siblings like reddit_ads_list_devices or reddit_ads_list_languages, but the resource is distinct enough to be recognizable.
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?
The phrase 'for targeting' gives a weak context hint, but there is no explicit when-to-use, when-not-to-use, or alternative tool guidance. An agent must infer usage entirely from the name and context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.