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 adds the useful constraint that only an enabled result should be selected, but omits return format and any auth/permission prerequisites for a customer-scoped call.

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 zero filler, and the core capability is front-loaded. The second sentence is slightly cryptic in its phrasing of the eligibility exclusion, but nothing is wasted.

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 tool with five parameters (four required), no output schema, no enums and 20% schema coverage, the description should explain input formats and what the result contains. It lists output fields (provider ID, country, type, status), which partially substitutes for the missing output schema, but leaves all four required inputs unexplained.

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 20% (just customer_id), and the description names no parameters explicitly except an oblique reference to location names. It gives no hint about locale format, country_code semantics, the location_names max of 10, or the connection_context pattern, 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?

States a specific verb ('resolve') and resource ('location names to provider IDs, country, type and status'), so the agent knows exactly what it returns without opening the schema. The trailing 'not account eligibility' implicitly distinguishes it from google_ads_account_eligibility_snapshot, though the sibling is not named outright.

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?

'Caller must select an enabled result' gives a real workflow constraint, and 'not account eligibility' establishes an exclusion. However, it never names the alternative tool to use for eligibility checks (e.g., google_ads_account_eligibility_snapshot) nor when this tool should precede another call.

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