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

Annotations already declare read-only, non-destructive, and open-world behavior, so the bar is lower. The description adds meaningful context: return composition as three lists, a visual-card presentation, and a default 30-day period, though it repeats 'Read-only' and does not discuss result limits or pagination.

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?

The description is front-loaded and reasonably compact, covering purpose, outputs, safety, and default period in a few sentences. 'Read-only' repeats the annotations and the visual-card note is peripheral, but overall there is little waste.

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 eight-parameter read-only analytics tool with no output schema, the description supplies the missing return-value overview and default period. Parameter selection is left to the fully documented schema, so it is complete enough, though exact result structure and row limits are only summarized.

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 100%, so the parameter-level meaning is already handled thoroughly in the schema. The description only mentions the default 30-day period, which duplicates the date_range schema description and adds no new parameter semantics.

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 specific analysis: real search terms that triggered Google Ads, and enumerates three output lists, so an agent can tell this is an insight tool rather than a raw search-term listing. It does not explicitly contrast with siblings such as google_ads_search_terms, so it stops short of 5.

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?

It opens with 'Use this to analyse...' and the three output lists imply use cases for keyword expansion, negative keyword candidates, and wasted single words. However, it gives no when-not guidance and does not name alternative tools for those same needs.

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