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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing a hard limitation (proximity/radius targets are not returned), warning that locations=[] does not imply worldwide coverage, and prescribing a verification path. These are exactly the caveats that prevent an agent from drawing a wrong conclusion from an empty result.

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?

Front-loaded with the resource and its two components, and every clause carries information. The dense parenthetical plus em-dash asides make it slightly harder to parse than it needs to be, but nothing is padding.

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?

An output schema exists, so return shape is covered elsewhere; the description still covers filter behavior, the coverage limitation, and the workspace parameter. The remaining hole is campaign_id format and multi-campaign behavior, which an agent needs in order to call it correctly.

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 0%, so the description must carry the burden. It does well for workspace ('Slug des Kunden-Workspace, optional bei nur einem Workspace') but only alludes to campaign_id via 'Optional auf eine Kampagne gefiltert' without saying whether it takes the numeric ID, resource name, or a list.

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 concrete resource and scope: per-campaign geo targeting, covering both the location criteria and the PRESENCE vs PRESENCE_OR_INTEREST setting. It clearly reads settings rather than performance (unlike ads_geo_performance) and clearly does not write (unlike ads_update_geo_targeting), though it never names those siblings explicitly.

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?

Gives real usage context: the campaign filter is optional, PRESENCE_OR_INTEREST is flagged as the usual cause of geo-leakage, and the agent is told to cross-check in the Google Ads UI when in doubt. No explicit when-not-to-use or named alternative tool, so not a 5.

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