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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description does add real behavioral context beyond that: restricted services require fresh server-verified access and otherwise refuse, and there are no writes or access grants. The gap is that 'restricted services' is left undefined and no return/scope behavior is described.

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 with the purpose front-loaded and no filler. The phrasing is dense with undefined terms ('bounded', 'native', 'restricted services'), which costs a little clarity, but the structure is otherwise efficient.

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?

No output schema exists, so the description could carry more about what the insight returns, but it does not. For a read-only tool whose annotations already cover safety, it is minimally adequate, yet the empty body object and connection_context remain unexplained and the access precondition is vague. There are clear remaining gaps.

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 only 33%: customer_id is documented, but body (an empty nested object) and connection_context (pattern-only) are undocumented in both schema and description. The description adds no parameter meaning whatsoever, so it fails to compensate for the low coverage. With effectively one meaningful documented parameter, this is below the baseline.

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 gives a verb (Read) and a resource (audience_dates insight), so the general action is clear. However, 'bounded native audience_dates insight' is opaque jargon and the description never distinguishes this from close siblings like google_ads_audience_attributes or google_ads_benchmark_dates. An agent knows it reads something, but not clearly what or how it differs.

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 explicit when-to-use guidance and no named alternative among the many audience/insight siblings. The only conditional statement ('Restricted services require fresh server-verified access and otherwise refuse') is a precondition, not a routing rule. The agent must infer usage from the name alone.

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