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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the read-only nature is covered. The description does add genuine behavioral context by disclosing a failure mode ('restricted services ... otherwise refuse') and access requirements, though 'No writes or access grants' largely restates the annotations.

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, front-loaded sentences with no filler. It is efficient, though terms like 'bounded' and 'native' spend words without adding clarity.

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 read tool with a required nested body object and no output schema, the description omits what the returned insight contains and gives no indication of the body semantics. With only 33% schema coverage, the description is too thin to make the tool reliably callable.

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 only 33%: only customer_id is documented, while the nested body fields (channel_ids, country_ids, planning_group) and connection_context carry no descriptions. The description adds no meaning about any parameter, so it fails to compensate for the coverage 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 names a read operation and a resource ('creator_channels insight'), which distinguishes it from mutation siblings. However, 'bounded native ... insight' is vague jargon that doesn't tell an agent what data is actually returned or how it differs from adjacent insight tools like google_ads_audience_attributes or google_ads_trending_topics.

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 when-to-use guidance and no named alternative among the many sibling insight/attribute tools. The only contextual hint is that restricted services need fresh server-verified access, which is a precondition rather than usage orientation.

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