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

With annotations already declaring destructiveHint=true, idempotentHint=false and readOnlyHint=false, the description adds real workflow context: the draft is not pushed to Google Ads, a draftId is returned, and publishing is a separate, later call that pushes 'as paused.' It leaves one gap: it never explains why saving a draft is flagged destructive, which the annotation implies.

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 'ADVANCED MODE' warning and the essential workflow in a short space. The closing sentence restates purpose already stated in the first sentence and reintroduces the preferred-way confusion, so it does not fully earn 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?

There is no output schema, so the description correctly supplies the return value (draftId) and the two-step publish workflow. But for an 11-parameter, mostly-required tool at 9% schema coverage, it omits any guidance on the campaign-structure parameters, leaving a meaningful gap for such a complex schema.

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 9% across 11 parameters (8 required), and the description contributes no parameter meaning at all — no explanation of brandId, adGroups, targetCpa, landingPageUrl, or the nested keyword/headline/description structures. The lone documented field (country) is covered by the schema, not the description, so it does not compensate for the coverage 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: it 'persists a campaign structure that Claude designed manually' and 'Returns a draftId.' It clearly names and contrasts with the sibling generate_campaign_draft. However, it undercuts itself with the closing claim that this is 'the new preferred way to create a campaign,' which sits awkwardly against the opening 'for most flows, use generate_campaign_draft instead.'

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?

Explicitly names the alternative (generate_campaign_draft) and the condition that selects this tool (advanced/manual design flows). It also names the prerequisite (fetch_keyword_forecasts to see planner data) and the required follow-up (publish_campaign_to_google_ads with the draftId). This is close to a complete when/when-not/alternatives guide.

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