get_asset_performance

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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful context by specifying the return kind (performance labels) and filter scope, but does not disclose other behavioral traits such as data aggregation, label thresholds, or response shape.

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 concise and well-structured: a clear one-sentence purpose followed by an Args list with each parameter on its own line. There is no redundant or filler content.

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 lookup tool with only one required parameter, the description is largely complete: it states the domain (PMax), the purpose, the output labels, and the optional filters. It could be slightly more explicit about what is returned when no filters are provided, but the overall context is sufficient.

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 0%, so the description carries the burden of explaining parameters. It provides one-line explanations for all three parameters, including that campaign_id and asset_group_id are optional filters, which adds meaning beyond the bare property names.

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 a specific verb ('Get'), resource ('asset-level performance labels'), and scope ('for PMax'). It also names the output labels (BEST, GOOD, LOW), which distinguishes it from sibling performance tools that operate at campaign, ad group, keyword, or placement level.

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 makes the use case clear: retrieving PMax asset-level performance labels, with optional filtering by campaign and asset group. It does not explicitly name alternatives or state when not to use the tool, but the asset-level and PMax context is enough to guide selection.

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