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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds useful behavioral detail by disclosing the default sort order (by spend), which shapes how results are consumed, but it says nothing about row limits, default account resolution when several accounts exist, or whether results aggregate across campaigns.

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?

Two tight sentences with the content/grain stated first and the use case second; nothing is wasted. Slightly held back from 5 because the second sentence is soft ('useful for') rather than routing the agent to a concrete next tool.

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?

All six parameters are optional, there is no output schema, and the description compensates by naming the fields returned and the sort order. Missing only the linkage to sibling tools and account-resolution behavior, which matters given the openWorldHint and folder/account scoping options.

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 83%, so parameter meaning is largely carried by the structured fields themselves (account vs folder scoping, date_range default of LAST_7_DAYS, start/end date pairing). The description adds no parameter-level detail, so the baseline 3 for high-coverage schemas applies.

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 the specific resource (search terms that triggered ads), the metrics returned (spend and conversions), and the ordering (sorted by spend), so an agent knows exactly what data comes back. It does not differentiate itself from close siblings like google_ads_search_term_insights or google_ads_wasted_spend, leaving overlap ambiguous.

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 clause 'Useful for finding wasted spend and negative keywords' implies the intended use case and hints at a follow-up action (negative keyword creation), but there is no explicit when-not guidance or named alternative such as search_term_insights for trend/diagnostic questions.

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