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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds that each test carries cells, dates and status, which is genuinely useful return-shape context given no output schema exists, but it says nothing about pagination, permissions, or whether inactive/completed tests are included.

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?

It is a single short sentence with no padding, but it is a sentence fragment whose phrasing ('on the ad account's business') is opaque and could be read as scoping to a business entity rather than the ad account. Brevity is achieved at the cost of grammatical clarity.

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 read-only list tool with three fully documented parameters and safety annotations, the definition is minimally sufficient. However, the absent action verb and the lack of any indication of result scope or volume leave the agent with a partially formed picture of what invoking it will produce.

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 coverage is 100% and all three parameters (folder, account, language) are documented in the schema, including the enum for language and the optional-account note. The description adds no meaning beyond that, so the baseline 3 applies.

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 sentence names the resource (A/B tests / split tests) and the fields returned (cells, dates, status), but supplies no verb — an agent must infer that this retrieves existing tests rather than creating them. The distinction from the sibling meta_create_ab_test is only implied by omission, not stated.

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?

There is no when-to-use guidance, no prerequisites, and no explicit alternative named. A reader can guess this is the read counterpart to meta_create_ab_test, but nothing in the text confirms that or says when A/B test data should be pulled versus using meta_performance or meta_insights_query.

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