Asset group signals

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds real context beyond that: it enumerates what comes back (signal_id, approval status, enabled account audiences, empty-state insights). It does not cover permissions, rate limits, or any pagination/truncation behavior, so it sits at the baseline-plus level rather than rich.

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 purpose is front-loaded in the first sentence and the second paragraph is a compact enumeration of returned fields. It is slightly wasteful because return-value detail largely duplicates the output schema, but there is no filler or hedging.

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?

With an output schema present, the description need not explain return values, and annotations carry the safety profile; the schema carries parameter docs. What remains missing is only the usage/routing context relative to siblings like draft_asset_group_signals and get_audience_lists, which is a modest gap for a two-parameter read tool.

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 both parameters (customer_id, asset_group_id) are already documented in the schema, including the useful 'from get_pmax_performance' provenance hint. The description adds no parameter-level meaning at all, so the baseline 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?

The description gives a specific verb and resource: 'Search themes and the audience signal of a Performance Max asset group, plus the account's audiences.' An agent can tell this is a read of PMax signal state, distinct from most siblings. It does not, however, name its closest sibling (draft_asset_group_signals), which is the mutating counterpart an agent would need to disambiguate against.

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?

There is no explicit when-to-use or when-not-to-use guidance. Nothing tells the agent whether to call this before draft_asset_group_signals, or how it relates to get_audience_lists / get_pmax_performance, which return overlapping data. The only hint is the mention of 'insights when a group has no themes or no audience signal', which is behavioral, not usage guidance.

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