List ad unit mappings

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

Annotations already declare readOnlyHint=true, so the safety profile is known. The description adds the scoping to 'attached to an AdMob ad unit' and clarifies that mappings are third-party network placements, but it does not disclose pagination behavior or return format. This is modest value beyond annotations.

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 a single, front-loaded sentence with a clear verb and resource. It avoids redundant detail and is appropriately concise for the tool's complexity.

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 simple list tool with annotations covering safety and schema covering all parameters, the description is sufficient. It states the primary function and scope. Lack of an output schema is mitigated by the clear statement that it lists mappings, though it could mention pagination explicitly.

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 baseline is 3. The description adds no additional parameter semantics beyond what the schema already provides (e.g., adUnitId format, pageSize, pageToken). The schema does the heavy lifting here.

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 clearly states the tool lists ad unit mappings (third-party network placements) attached to a specific AdMob ad unit. This distinguishes it from siblings like list_ad_units (which lists ad units themselves) and create_ad_unit_mapping (which creates mappings).

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 usage when you need mappings for a given ad unit, but it does not explicitly say when to use this tool instead of alternatives like list_ad_units. No exclusions or alternative names are mentioned, so guidance is implied rather than explicit.

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