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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior. The description adds useful context by enumerating the returned campaign attributes, including status values and performance metrics, though it does not mention pagination or ordering.

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 front-loaded sentence with no wasted clauses. It is slightly dense with return-field enumeration, but still efficient and readable.

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?

With zero parameters, safety annotations, and an output schema, the description provides enough context for correct invocation. It could be stronger by clarifying whether it covers all accounts or workspaces and how results are ordered or paginated.

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 has zero parameters, which is the baseline for a 4. The description does not need to explain parameter semantics and correctly focuses on the returned data.

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 identifies the resource and scope: 'Every ad campaign' with the fields it returns. It implicitly contrasts with the singular sibling get_ad_campaign, but does not explicitly name alternatives or differentiate from ad_performance or ads_overview.

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 'Every ad campaign' implies exhaustive listing and distinguishes it from a single-campaign getter. However, the description does not explicitly say when to use this tool instead of siblings like get_ad_campaign, ad_performance, or ads_overview.

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