ads_run_gaql

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

With no annotations, the description carries the behavioral burden. It explicitly identifies the tool as a read tool and discloses the client-side row cap with a default of 200. It doesn't cover error handling or authentication, but the read-only nature and row-limiting behavior are the key traits an agent needs.

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?

Well-structured: purpose sentence, usage note, a clear example query, then a tight Args list. Every line earns its place and the example adds practical value without fluff.

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 an arbitrary-query tool, the description covers the essentials: what it does, when to use it, how to construct the query, account id format, and row limits. The output schema already exists, so return-value documentation is not needed. Nothing critical 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?

Schema description coverage is 0%, so the description must fully document parameters. It does: customer_id is explained as a 10-digit account id with dashes allowed, query is 'full GAQL query string,' and limit is a max-rows client-side cap with default 200. This fully compensates for the empty schema descriptions.

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?

Opens with a specific verb and resource: 'Run an arbitrary GAQL query and return rows.' The 'most flexible read tool' framing explicitly differentiates it from narrower reporting siblings like ads_campaign_performance and ads_keyword_performance, and the example query makes the purpose concrete.

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?

States clearly to use it for 'any custom report,' which is actionable context. It does not explicitly name alternatives or exclusion conditions, but the custom-vs-prebuilt distinction is strong enough for an agent to route correctly.

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