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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so 'Read-only' is mostly redundant. The description adds a useful downstream-usage note but says nothing about matching behavior (exact vs fuzzy), result limits, or what is returned when no match is found.

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?

A single tight sentence with the purpose front-loaded and the downstream use stated at the end. The trailing 'Read-only' duplicates the annotations and is the only wasted clause.

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 three-parameter, fully documented read-only lookup, the essentials are covered. But with no output schema, the description never describes the shape of returned targeting values (IDs, keys, names), which an agent needs to correctly build the subsequent x_ads_create_campaign call.

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 100%, with each parameter documented, including an example for query and the guidance that language should match the user's writing language. The description adds no parameter-level meaning beyond the schema, so the baseline of 3 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 a specific verb (search) plus resource (X Ads targeting locations) with scope (countries, regions, cities) and the downstream purpose: returning targeting values for x_ads_create_campaign. This clearly distinguishes it from add-style siblings like x_ads_add_locations and from other platforms' location lookups.

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 description implies when to use it: before calling x_ads_create_campaign to resolve place names into targeting values. It does not explicitly contrast with sibling lookups (google_ads_find_locations, tiktok_search_locations) or state exclusions such as not being the tool for attaching locations to an existing campaign.

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