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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces this with 'Does not write to an ad account.' Beyond annotations it adds genuinely useful context: the credit cost (1 credit), validation behavior (character limits, final-URL https check), and that the return value is a file link. It does not contradict any annotation.

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?

Dense, front-loaded telegraphic sentences with essentially no filler; the output formats lead and constraints follow. The clipped fragments make it slightly harder to parse than a flowing sentence would be, but every clause earns its place.

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 no output schema, the description correctly compensates by stating 'Returns a file link,' and it covers cost, safety, and validation. But for a 7-parameter tool at 14% schema coverage it leaves most input semantics unspecified, so it is adequate rather than complete.

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 only 14% (only 'brand' is documented), so the description must carry the burden for the other six parameters, and it largely does not. It only obliquely references finalUrl (the https check) and target (Google vs Meta); headlines, descriptions, campaign, and adGroup semantics go unaddressed.

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 states the concrete deliverable precisely: a Google Ads Editor CSV (responsive search ad, paused) or a Meta bulk-import sheet (paused), naming both output variants keyed to the target enum. It is clearly a draft-generation/export tool, though it doesn't explicitly contrast itself with the nearest sibling (draft_ad_variants).

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 artifact types (you use this to produce an import file for Google or Meta), and the parenthetical 'paused' plus https/character checks hint at pre-launch drafting. However, there is no explicit when-to-use guidance vs draft_ad_variants or any exclusion criteria.

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