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

Annotations only declare readOnlyHint/openWorldHint; the description adds substantial behavior: a hard 100-ad limit with no truncation indicator, silent hiding of REMOVED ads and ads under removed groups/campaigns, and that ad_group_status/campaign_status reveal paused parents that keep an ENABLED ad from serving. These are exactly the traps an agent needs 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?

Front-loaded with the resource and returned fields, and every sentence carries operational information. It is dense and packs several facts per sentence, making it slightly harder to scan, but nothing is filler.

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?

An output schema exists, so return values need no explanation, and the description still covers the field set, the result cap, filtering strategy, removal/parent-status edge cases, and the PMax exception. Nothing an agent needs to call this correctly is missing.

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 and does explain all three parameters: workspace is a customer slug optional when only one workspace exists, and campaign_id/ad_group_id are scoping filters for large accounts. It stops short of stating ID formats or precedence when both filters are supplied, which is the remaining gap.

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?

States a specific verb and resource ('Anzeigen auflisten') and enumerates the returned fields (Headlines, Descriptions, URLs, Status, Approval). It explicitly distinguishes itself from the sibling ads_list_asset_groups for PMax campaigns, so an agent can tell the two apart without opening a schema.

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?

Gives concrete when-to-use guidance: narrow with campaign_id or ad_group_id on larger accounts because of the 100-ad cap. It also names the alternative tool for PMax (ads_list_asset_groups) and the condition that selects it, plus the workspace-optional case.

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