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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. Beyond that the description discloses real behavioral traits: refresh triggers a provider fetch, reporting cadence is daily rather than real time, null results mean a report is not yet available, and errorCode should be localized. These are meaningful operational details not present in annotations.

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-loads the resource and returned fields, then layers behavioral notes (refresh, null semantics, pagination, error localization) in a tight sequence. The sentences are dense but each conveys actionable information, with no 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?

For a read-only tool with annotations, no output schema, and four parameters, the description is nearly complete: it names returned metrics, explains the refresh and reporting-cadence behavior, notes null results, and addresses pagination. The only meaningful gap is that individual parameters like campaignId and limit remain unexplained.

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 must carry parameter meaning. It explains refresh (fetches latest provider report), implies pagination via nextOffset, and hints at error handling, but limit, offset, and campaignId get no real explanation, and 'nextOffset' does not map cleanly to the schema's 'offset' parameter, which risks confusion.

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 (read) and resource (the current user's ChatGPT ad drafts, campaigns and results) and enumerates the returned metrics, so the agent knows exactly what data it exposes. It does not, however, differentiate itself from related siblings like list_ad_campaigns, get_ad_wallet, or get_analytics_overview, leaving the agent to infer the boundary.

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?

Provides usage context for the refresh flag ('Set refresh=true to fetch the latest provider report; reporting is daily, not real time'), which is genuinely helpful. But there is no explicit when-to-use guidance against alternatives such as list_ad_campaigns or the other ad-sibling tools, so routing is only implied.

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