list_ads

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the default cap of 50 ads and the allowed status_filter values, but says nothing about pagination beyond the limit, ordering, or what 'approval status' looks like in the response. Useful additions, but behavior remains only partially disclosed.

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 one-line summary is front-loaded and the Args block is terse, one clause per parameter with no filler. The docstring-style layout is slightly mechanical but nothing is redundant or padded.

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 read-only list tool with four parameters and no output schema, the description covers invocation adequately but leaves the return shape undefined — an agent cannot tell whether ads come back with ids, creative content, or approval-state enums, nor whether truncation at the limit is signalled. That gap is the main thing an output schema would otherwise have covered.

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 full burden and largely meets it: it explains customer_id as a Google Ads customer ID, ad_group_id as the ad group, limit's default of 50, and — critically — enumerates the three legal status_filter values ('ENABLED', 'PAUSED', 'REMOVED'), which the schema does not express since the field is an unconstrained anyOf string/null. Only the exact format of customer_id (dashes vs. digits) is left unstated.

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 opens with a specific verb and resource ('List ads in an ad group') plus the scope qualifier 'with approval status', which separates it from get_ad_details (single ad) and list_ad_groups (parent resource). It stops short of naming any sibling explicitly, so differentiation is implied by scope rather than stated.

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?

Usage is implied by the required ad_group_id parameter: call this to enumerate ads under one ad group. There is no explicit guidance on when to prefer this over get_ad_details or execute_gaql for ad queries, and no stated prerequisites such as needing an accessible customer ID.

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