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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, covering safety. The description adds that it includes creatives and performance metrics, which is useful context, but does not elaborate on pagination, filtering behavior, or auth requirements. Since annotations cover the safety profile, a 3 is appropriate.

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?

The description is a single, compact sentence that efficiently conveys the core purpose and key data points. It contains no redundant words, earning a high conciseness score, though it could be slightly more structured with a list of metrics, but it is still well within acceptable bounds.

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 tool with 5 optional parameters and no output schema, the description is incomplete. It mentions some return metrics but fails to explain parameter semantics, default behaviors (e.g., include_paused=false), or how to scope the query (since/until). The single sentence is too sparse to fully guide an agent, especially given the lack of schema coverage.

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 0%, and the description provides zero information about the parameters (since, until, account, auth_account, include_paused). It fails to explain their meaning or usage, leaving the agent without guidance. With no coverage and no compensation, this is a critical 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?

The description clearly states it lists ads with creatives and performance insights, using the specific verb 'List' and resource 'ads'. It mentions specific content (image, video, copy) and metrics (spend, revenue, ROAS, actions), distinguishing it from sibling tools like meta_ads_campaigns or meta_ads_adset_detail.

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 description implies it is for listing ads, but provides no explicit guidance on when to use this tool over alternatives such as meta_ads_realtime or meta_ads_roas, nor any exclusions. It could benefit from mentioning scenarios where other tools are more appropriate, but the basic context is implied.

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