google ads search fields

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is fully covered. The description adds non-redundant context: the catalog is 'live' (not cached), and the discovery scope includes compatibility relationships between fields. These traits are consistent with the annotations, and no contradiction exists.

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?

Three short sentences with zero waste: the verb-resource pairing is front-loaded, the scope claim earns its place, and the usage context closes efficiently. Every sentence contributes information not available elsewhere in the structured fields.

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 a rich output schema present, return values need no description. The description, annotations, and 100%-covered schema collectively give an agent everything needed to call it correctly. Minor gap: the precedence between the raw 'query' param and the structured filters (query replaces filters) is documented only in the schema, not synthesized into the description.

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 schema fully documents all 8 parameters including defaults and pagination semantics. The description adds no parameter-level detail beyond loosely mirroring the category enum (RESOURCE, ATTRIBUTE, SEGMENT, METRIC) in its scope statement. Baseline 3 is appropriate since the schema carries the load.

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 names a specific action ('Search'), a specific resource ('Google's live GoogleAdsField catalog'), and an explicit scope ('every queryable GAQL resource, attribute, segment, metric, enum value, and selectable-with compatibility relationship'). It also orients the agent among ~35 siblings by positioning this as metadata discovery ('useful before a raw GAQL query'), clearly distinguishing it from run_gaql and validate_query.

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?

'Useful before a raw GAQL query' gives clear contextual timing for when this should be invoked in a workflow. However, it never explicitly names alternatives (e.g., google_ads_run_gaql, google_ads_validate_query) or states when NOT to use it, so the agent must infer the contrast from sibling names rather than being told.

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