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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds a useful conditional behaviour: when product_ref is supplied, each row includes product_link. It says nothing about ordering, pagination, or result limits.

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?

Three short sentences, front-loaded with the core action, then disambiguation, then the parameter nuance. Every sentence contributes; nothing is bloated.

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?

An output schema exists, so return-value explanation isn't required, and read-only safety is in annotations. The filtering semantics of product_ref are covered. The only real gap is that connection_context's purpose is never addressed.

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 0%, so the description must carry the load. It explains product_ref's filtering effect and its side effect on row shape, which is genuinely useful. connection_context is left entirely unexplained in both schema and description.

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?

States a specific verb and resource: 'List saved reusable Google ad templates.' It also pre-empts a likely misread by saying these are ad-creation templates, not an insights breakdown. It doesn't explicitly distinguish itself from nearby siblings like google_ads_product_cards_list or google_ads_template_reverse_engineer.

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?

Gives one conditional usage rule for product_ref ('when product cards are enabled'), which is helpful. But it never says when to choose this tool over product_cards_list or template_reverse_engineer, and no prerequisites for connection_context are stated.

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