List all ad accounts

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-world profile is covered. The description adds only the 'grouped by business' shape hint; it says nothing about pagination, result volume, or ordering. With annotations carrying the safety burden, this is an adequate but not rich disclosure.

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 tight sentences with the resource/scope claim front-loaded and the actionable 'start here' guidance second. Nothing is wasted.

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 zero-param, read-only list tool whose annotations already cover safety and open-world behavior, the description covers what it returns and when to reach for it. Without an output schema it could say more about pagination or ordering, but nothing essential for correct invocation is missing.

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?

The tool takes no parameters, so there is no parameter semantics to convey; the baseline for zero-param tools is 4. The description does not need to compensate for any schema gap.

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?

A specific verb and resource are stated ('List every ad account'), and scope is clarified ('the authenticated user can access, grouped by business'), which implicitly separates it from the business-scoped sibling. It stops short of naming an alternative like reddit_ads_list_business_ad_accounts or reddit_ads_query_ad_accounts explicitly.

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?

'Start here to find ad_account_id values' gives a clear entry-point condition that tells an agent when this tool is the right first call. There is no explicit exclusion or named alternative for when a business-scoped or query variant is preferable.

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