List AdMob ad units

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

Annotations declare readOnlyHint=true, which the description supports. The description adds value by listing the returned fields (ad unit ID, format, app) but does not disclose pagination behavior; however, this is partially covered by schema parameter descriptions.

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, focused sentence with no fluff. Every word contributes to the purpose and output understanding.

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 read-only listing tool, the description covers purpose and return information, and pagination is implied via the pageToken parameter in the schema. It could explicitly mention pagination behavior, but overall it is sufficient given the schema's richness.

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 clear descriptions for pageSize and pageToken. The description does not add parameter-level detail, but the schema already handles it, so the baseline of 3 is appropriate.

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?

Description specifies the verb 'Lists' and the resource 'ad units in the AdMob account', and includes return fields (ad unit ID, format, app). This clearly distinguishes from sibling list tools like list_apps and create_ad_unit.

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 clearly implies a listing use case and matches the readOnlyHint, but it does not explicitly state when to use this tool versus alternatives or provide exclusion criteria. It provides clear context without exclusions.

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